From 72c9f56c663645c0faf5fdb31ec31e15de2c0229 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sun, 13 Aug 2023 13:05:26 +0200
Subject: [PATCH] LibJS: Make Heap::allocate<T>() infallible

Stop worrying about tiny OOMs. Work towards #20449.

While going through these, I also changed the function signature in many
places where returning ThrowCompletionOr<T> is no longer necessary.
---
 .../BindingsGenerator/IDLGenerators.cpp       |   2 +-
 .../GenerateWindowOrWorkerInterfaces.cpp      |   8 +-
 Tests/LibWasm/test-wasm.cpp                   |   2 +-
 .../Applications/Spreadsheet/Workbook.cpp     |   2 +-
 .../LibJS/Contrib/Test262/262Object.cpp       |   4 +-
 .../LibJS/Contrib/Test262/GlobalObject.cpp    |   2 +-
 Userland/Libraries/LibJS/Heap/Heap.h          |   4 +-
 Userland/Libraries/LibJS/Module.cpp           |   2 +-
 .../LibJS/Runtime/AbstractOperations.cpp      |   2 +-
 .../LibJS/Runtime/AbstractOperations.h        |   2 +-
 .../LibJS/Runtime/AggregateError.cpp          |   2 +-
 Userland/Libraries/LibJS/Runtime/Array.cpp    |   2 +-
 .../Libraries/LibJS/Runtime/ArrayBuffer.cpp   |   6 +-
 .../Libraries/LibJS/Runtime/ArrayIterator.cpp |   2 +-
 .../LibJS/Runtime/AsyncFromSyncIterator.cpp   |   2 +-
 .../Runtime/AsyncFunctionDriverWrapper.cpp    |   4 +-
 .../Runtime/AsyncFunctionDriverWrapper.h      |   2 +-
 .../LibJS/Runtime/AsyncGenerator.cpp          |   2 +-
 .../Libraries/LibJS/Runtime/BigIntObject.cpp  |   2 +-
 .../Libraries/LibJS/Runtime/BooleanObject.cpp |   2 +-
 .../Libraries/LibJS/Runtime/BoundFunction.cpp |   2 +-
 Userland/Libraries/LibJS/Runtime/DataView.cpp |   2 +-
 Userland/Libraries/LibJS/Runtime/Date.cpp     |   2 +-
 .../Runtime/ECMAScriptFunctionObject.cpp      |   8 +-
 Userland/Libraries/LibJS/Runtime/Error.cpp    |  48 ++--
 .../LibJS/Runtime/GeneratorObject.cpp         |   2 +-
 .../Runtime/Intl/CollatorCompareFunction.cpp  |   2 +-
 .../Runtime/Intl/DateTimeFormatFunction.cpp   |   2 +-
 .../Libraries/LibJS/Runtime/Intl/Locale.cpp   |   2 +-
 .../Runtime/Intl/NumberFormatFunction.cpp     |   2 +-
 .../LibJS/Runtime/Intl/SegmentIterator.cpp    |   2 +-
 .../Libraries/LibJS/Runtime/Intl/Segments.cpp |   2 +-
 .../Libraries/LibJS/Runtime/Intrinsics.cpp    | 126 ++++-----
 Userland/Libraries/LibJS/Runtime/Iterator.cpp |   4 +-
 Userland/Libraries/LibJS/Runtime/Iterator.h   |   2 +-
 .../LibJS/Runtime/IteratorConstructor.cpp     |   2 +-
 .../LibJS/Runtime/IteratorHelper.cpp          |   2 +-
 .../LibJS/Runtime/IteratorPrototype.cpp       |   2 +-
 Userland/Libraries/LibJS/Runtime/Map.cpp      |   2 +-
 .../Libraries/LibJS/Runtime/MapIterator.cpp   |   2 +-
 .../LibJS/Runtime/NativeFunction.cpp          |   4 +-
 .../Libraries/LibJS/Runtime/NumberObject.cpp  |   2 +-
 Userland/Libraries/LibJS/Runtime/Object.cpp   |   6 +-
 Userland/Libraries/LibJS/Runtime/Promise.cpp  |   2 +-
 .../LibJS/Runtime/PromiseCapability.cpp       |   2 +-
 .../PromiseResolvingElementFunctions.cpp      |   8 +-
 .../Runtime/PromiseResolvingFunction.cpp      |   2 +-
 .../Libraries/LibJS/Runtime/ProxyObject.cpp   |   2 +-
 .../Libraries/LibJS/Runtime/RegExpObject.cpp  |   4 +-
 .../LibJS/Runtime/RegExpStringIterator.cpp    |   2 +-
 Userland/Libraries/LibJS/Runtime/Set.cpp      |   2 +-
 .../Libraries/LibJS/Runtime/SetIterator.cpp   |   2 +-
 .../LibJS/Runtime/StringConstructor.cpp       |   2 +-
 .../LibJS/Runtime/StringIterator.cpp          |   2 +-
 .../Libraries/LibJS/Runtime/StringObject.cpp  |   4 +-
 .../Libraries/LibJS/Runtime/StringObject.h    |   2 +-
 .../LibJS/Runtime/SuppressedError.cpp         |   2 +-
 .../Libraries/LibJS/Runtime/SymbolObject.cpp  |   2 +-
 .../LibJS/Runtime/Temporal/Temporal.cpp       |   2 +-
 .../Libraries/LibJS/Runtime/TypedArray.cpp    | 262 +++++++++---------
 Userland/Libraries/LibJS/Runtime/Value.cpp    |   2 +-
 Userland/Libraries/LibJS/Runtime/WeakMap.cpp  |   2 +-
 Userland/Libraries/LibJS/Runtime/WeakRef.cpp  |   4 +-
 Userland/Libraries/LibJS/Runtime/WeakSet.cpp  |   2 +-
 .../LibJS/Runtime/WrappedFunction.cpp         |   2 +-
 .../Libraries/LibTest/JavaScriptTestRunner.h  |   2 +-
 .../LibWeb/Bindings/MainThreadVM.cpp          |   2 +-
 .../LibWeb/Bindings/OptionConstructor.cpp     |   2 +-
 .../Libraries/LibWeb/CSS/CSSFontFaceRule.cpp  |   4 +-
 .../Libraries/LibWeb/CSS/CSSFontFaceRule.h    |   2 +-
 .../Libraries/LibWeb/CSS/CSSImportRule.cpp    |   4 +-
 Userland/Libraries/LibWeb/CSS/CSSImportRule.h |   2 +-
 .../Libraries/LibWeb/CSS/CSSKeyframeRule.cpp  |   4 +-
 .../Libraries/LibWeb/CSS/CSSKeyframeRule.h    |   2 +-
 .../Libraries/LibWeb/CSS/CSSKeyframesRule.cpp |   4 +-
 .../Libraries/LibWeb/CSS/CSSKeyframesRule.h   |   2 +-
 .../Libraries/LibWeb/CSS/CSSMediaRule.cpp     |   4 +-
 Userland/Libraries/LibWeb/CSS/CSSMediaRule.h  |   2 +-
 .../Libraries/LibWeb/CSS/CSSNamespaceRule.cpp |   4 +-
 .../Libraries/LibWeb/CSS/CSSNamespaceRule.h   |   2 +-
 Userland/Libraries/LibWeb/CSS/CSSRuleList.cpp |   8 +-
 Userland/Libraries/LibWeb/CSS/CSSRuleList.h   |   4 +-
 .../LibWeb/CSS/CSSStyleDeclaration.cpp        |   8 +-
 .../LibWeb/CSS/CSSStyleDeclaration.h          |   4 +-
 .../Libraries/LibWeb/CSS/CSSStyleRule.cpp     |   4 +-
 Userland/Libraries/LibWeb/CSS/CSSStyleRule.h  |   2 +-
 .../Libraries/LibWeb/CSS/CSSStyleSheet.cpp    |   4 +-
 Userland/Libraries/LibWeb/CSS/CSSStyleSheet.h |   2 +-
 .../Libraries/LibWeb/CSS/CSSSupportsRule.cpp  |   4 +-
 .../Libraries/LibWeb/CSS/CSSSupportsRule.h    |   2 +-
 Userland/Libraries/LibWeb/CSS/MediaList.cpp   |   4 +-
 Userland/Libraries/LibWeb/CSS/MediaList.h     |   2 +-
 .../Libraries/LibWeb/CSS/MediaQueryList.cpp   |   4 +-
 .../Libraries/LibWeb/CSS/MediaQueryList.h     |   2 +-
 .../LibWeb/CSS/MediaQueryListEvent.cpp        |   4 +-
 .../LibWeb/CSS/MediaQueryListEvent.h          |   2 +-
 .../Libraries/LibWeb/CSS/Parser/Helpers.cpp   |   8 +-
 .../Libraries/LibWeb/CSS/Parser/Parser.cpp    |  32 +--
 .../CSS/ResolvedCSSStyleDeclaration.cpp       |   4 +-
 .../LibWeb/CSS/ResolvedCSSStyleDeclaration.h  |   2 +-
 Userland/Libraries/LibWeb/CSS/Screen.cpp      |   4 +-
 Userland/Libraries/LibWeb/CSS/Screen.h        |   2 +-
 .../Libraries/LibWeb/CSS/StyleSheetList.cpp   |   4 +-
 .../Libraries/LibWeb/CSS/StyleSheetList.h     |   2 +-
 .../Libraries/LibWeb/CSS/VisualViewport.cpp   |   4 +-
 .../Libraries/LibWeb/CSS/VisualViewport.h     |   2 +-
 Userland/Libraries/LibWeb/Crypto/Crypto.cpp   |   6 +-
 Userland/Libraries/LibWeb/Crypto/Crypto.h     |   2 +-
 .../Libraries/LibWeb/Crypto/SubtleCrypto.cpp  |   4 +-
 .../Libraries/LibWeb/Crypto/SubtleCrypto.h    |   2 +-
 .../Libraries/LibWeb/DOM/AbortController.cpp  |   2 +-
 Userland/Libraries/LibWeb/DOM/AbortSignal.cpp |   4 +-
 .../LibWeb/DOM/AccessibilityTreeNode.cpp      |   4 +-
 .../LibWeb/DOM/AccessibilityTreeNode.h        |   2 +-
 Userland/Libraries/LibWeb/DOM/Attr.cpp        |  10 +-
 Userland/Libraries/LibWeb/DOM/Attr.h          |   4 +-
 Userland/Libraries/LibWeb/DOM/Comment.cpp     |   2 +-
 Userland/Libraries/LibWeb/DOM/CustomEvent.cpp |   4 +-
 Userland/Libraries/LibWeb/DOM/CustomEvent.h   |   4 +-
 .../LibWeb/DOM/DOMImplementation.cpp          |  14 +-
 .../Libraries/LibWeb/DOM/DOMImplementation.h  |   2 +-
 .../Libraries/LibWeb/DOM/DOMTokenList.cpp     |   4 +-
 Userland/Libraries/LibWeb/DOM/DOMTokenList.h  |   2 +-
 Userland/Libraries/LibWeb/DOM/Document.cpp    | 124 ++++-----
 Userland/Libraries/LibWeb/DOM/Document.h      |   4 +-
 .../Libraries/LibWeb/DOM/DocumentFragment.cpp |   2 +-
 .../Libraries/LibWeb/DOM/DocumentLoading.cpp  |   2 +-
 .../Libraries/LibWeb/DOM/DocumentType.cpp     |   4 +-
 Userland/Libraries/LibWeb/DOM/DocumentType.h  |   2 +-
 Userland/Libraries/LibWeb/DOM/Element.cpp     |  24 +-
 .../Libraries/LibWeb/DOM/ElementFactory.cpp   | 214 +++++++-------
 Userland/Libraries/LibWeb/DOM/Event.cpp       |   4 +-
 Userland/Libraries/LibWeb/DOM/Event.h         |   2 +-
 Userland/Libraries/LibWeb/DOM/EventTarget.cpp |   4 +-
 .../Libraries/LibWeb/DOM/HTMLCollection.cpp   |   4 +-
 .../Libraries/LibWeb/DOM/HTMLCollection.h     |   2 +-
 .../Libraries/LibWeb/DOM/IDLEventListener.cpp |   4 +-
 .../Libraries/LibWeb/DOM/IDLEventListener.h   |   2 +-
 .../Libraries/LibWeb/DOM/LiveNodeList.cpp     |   4 +-
 Userland/Libraries/LibWeb/DOM/LiveNodeList.h  |   2 +-
 .../Libraries/LibWeb/DOM/MutationObserver.cpp |   2 +-
 .../Libraries/LibWeb/DOM/MutationRecord.cpp   |   4 +-
 .../Libraries/LibWeb/DOM/MutationRecord.h     |   2 +-
 .../Libraries/LibWeb/DOM/NamedNodeMap.cpp     |   4 +-
 Userland/Libraries/LibWeb/DOM/NamedNodeMap.h  |   2 +-
 Userland/Libraries/LibWeb/DOM/Node.cpp        |  26 +-
 Userland/Libraries/LibWeb/DOM/NodeFilter.cpp  |   4 +-
 Userland/Libraries/LibWeb/DOM/NodeFilter.h    |   2 +-
 .../Libraries/LibWeb/DOM/NodeIterator.cpp     |   2 +-
 .../Libraries/LibWeb/DOM/NodeOperations.cpp   |  10 +-
 Userland/Libraries/LibWeb/DOM/ParentNode.cpp  |  16 +-
 Userland/Libraries/LibWeb/DOM/Range.cpp       |  26 +-
 Userland/Libraries/LibWeb/DOM/Range.h         |   6 +-
 .../Libraries/LibWeb/DOM/StaticNodeList.cpp   |   4 +-
 .../Libraries/LibWeb/DOM/StaticNodeList.h     |   2 +-
 Userland/Libraries/LibWeb/DOM/StaticRange.cpp |   2 +-
 Userland/Libraries/LibWeb/DOM/Text.cpp        |   4 +-
 Userland/Libraries/LibWeb/DOM/TreeWalker.cpp  |   4 +-
 Userland/Libraries/LibWeb/DOM/TreeWalker.h    |   2 +-
 .../Libraries/LibWeb/DOMParsing/InnerHTML.cpp |   2 +-
 .../LibWeb/DOMParsing/XMLSerializer.cpp       |   2 +-
 .../Libraries/LibWeb/Encoding/TextDecoder.cpp |   2 +-
 .../Libraries/LibWeb/Encoding/TextEncoder.cpp |   2 +-
 Userland/Libraries/LibWeb/Fetch/Body.cpp      |   2 +-
 Userland/Libraries/LibWeb/Fetch/BodyInit.cpp  |   4 +-
 .../Libraries/LibWeb/Fetch/FetchMethod.cpp    |   2 +-
 .../LibWeb/Fetch/Fetching/Fetching.cpp        |   4 +-
 Userland/Libraries/LibWeb/Fetch/Headers.cpp   |   2 +-
 .../LibWeb/Fetch/HeadersIterator.cpp          |   6 +-
 .../Libraries/LibWeb/Fetch/HeadersIterator.h  |   2 +-
 .../Fetch/Infrastructure/HTTP/Bodies.cpp      |   4 +-
 .../LibWeb/Fetch/Infrastructure/HTTP/Bodies.h |   2 +-
 .../Fetch/Infrastructure/HTTP/Requests.cpp    |   4 +-
 .../Fetch/Infrastructure/HTTP/Requests.h      |   2 +-
 .../Fetch/Infrastructure/HTTP/Responses.cpp   |   2 +-
 Userland/Libraries/LibWeb/Fetch/Request.cpp   |  18 +-
 Userland/Libraries/LibWeb/Fetch/Request.h     |   2 +-
 Userland/Libraries/LibWeb/Fetch/Response.cpp  |  18 +-
 Userland/Libraries/LibWeb/Fetch/Response.h    |   4 +-
 Userland/Libraries/LibWeb/FileAPI/Blob.cpp    |  20 +-
 Userland/Libraries/LibWeb/FileAPI/Blob.h      |   4 +-
 Userland/Libraries/LibWeb/FileAPI/File.cpp    |   2 +-
 .../Libraries/LibWeb/FileAPI/FileList.cpp     |   4 +-
 Userland/Libraries/LibWeb/FileAPI/FileList.h  |   2 +-
 .../Libraries/LibWeb/Geometry/DOMMatrix.cpp   |   6 +-
 .../LibWeb/Geometry/DOMMatrixReadOnly.cpp     |   4 +-
 .../Libraries/LibWeb/Geometry/DOMPoint.cpp    |   2 +-
 .../LibWeb/Geometry/DOMPointReadOnly.cpp      |   2 +-
 .../Libraries/LibWeb/Geometry/DOMRect.cpp     |  10 +-
 Userland/Libraries/LibWeb/Geometry/DOMRect.h  |   4 +-
 .../Libraries/LibWeb/Geometry/DOMRectList.cpp |   4 +-
 .../Libraries/LibWeb/Geometry/DOMRectList.h   |   2 +-
 .../LibWeb/Geometry/DOMRectReadOnly.cpp       |   6 +-
 .../LibWeb/Geometry/DOMRectReadOnly.h         |   2 +-
 Userland/Libraries/LibWeb/HTML/AudioTrack.cpp |   2 +-
 .../Libraries/LibWeb/HTML/BrowsingContext.cpp |  21 +-
 .../Libraries/LibWeb/HTML/CanvasGradient.cpp  |   6 +-
 .../Libraries/LibWeb/HTML/CanvasPattern.cpp   |   2 +-
 .../LibWeb/HTML/CanvasRenderingContext2D.cpp  |   6 +-
 .../LibWeb/HTML/CanvasRenderingContext2D.h    |   2 +-
 Userland/Libraries/LibWeb/HTML/CloseEvent.cpp |   4 +-
 Userland/Libraries/LibWeb/HTML/CloseEvent.h   |   2 +-
 .../CustomElements/CustomElementDefinition.h  |   2 +-
 Userland/Libraries/LibWeb/HTML/DOMParser.cpp  |   6 +-
 .../Libraries/LibWeb/HTML/DOMStringMap.cpp    |   4 +-
 Userland/Libraries/LibWeb/HTML/DOMStringMap.h |   2 +-
 Userland/Libraries/LibWeb/HTML/ErrorEvent.cpp |   4 +-
 Userland/Libraries/LibWeb/HTML/ErrorEvent.h   |   2 +-
 Userland/Libraries/LibWeb/HTML/Focus.cpp      |   4 +-
 .../Libraries/LibWeb/HTML/FormDataEvent.cpp   |   2 +-
 .../LibWeb/HTML/HTMLCanvasElement.cpp         |   4 +-
 .../LibWeb/HTML/HTMLDetailsElement.cpp        |   2 +-
 .../Libraries/LibWeb/HTML/HTMLDocument.cpp    |   4 +-
 Userland/Libraries/LibWeb/HTML/HTMLDocument.h |   2 +-
 .../Libraries/LibWeb/HTML/HTMLElement.cpp     |   4 +-
 .../Libraries/LibWeb/HTML/HTMLFormElement.cpp |   6 +-
 .../LibWeb/HTML/HTMLIFrameElement.cpp         |   2 +-
 .../LibWeb/HTML/HTMLImageElement.cpp          |  14 +-
 .../LibWeb/HTML/HTMLInputElement.cpp          |  26 +-
 .../Libraries/LibWeb/HTML/HTMLLinkElement.cpp |  12 +-
 .../LibWeb/HTML/HTMLMediaElement.cpp          |  97 +++----
 .../Libraries/LibWeb/HTML/HTMLMediaElement.h  |   6 +-
 .../LibWeb/HTML/HTMLObjectElement.cpp         |   6 +-
 .../LibWeb/HTML/HTMLOptionsCollection.cpp     |   4 +-
 .../LibWeb/HTML/HTMLOptionsCollection.h       |   2 +-
 .../LibWeb/HTML/HTMLScriptElement.cpp         |  10 +-
 .../LibWeb/HTML/HTMLSelectElement.cpp         |   2 +-
 .../LibWeb/HTML/HTMLTableElement.cpp          |   4 +-
 .../LibWeb/HTML/HTMLTableRowElement.cpp       |   2 +-
 .../LibWeb/HTML/HTMLTableSectionElement.cpp   |   2 +-
 .../LibWeb/HTML/HTMLTemplateElement.cpp       |   2 +-
 Userland/Libraries/LibWeb/HTML/History.cpp    |   4 +-
 Userland/Libraries/LibWeb/HTML/History.h      |   2 +-
 Userland/Libraries/LibWeb/HTML/ImageData.cpp  |   2 +-
 .../Libraries/LibWeb/HTML/MessageChannel.cpp  |   6 +-
 .../Libraries/LibWeb/HTML/MessageEvent.cpp    |   4 +-
 Userland/Libraries/LibWeb/HTML/MessageEvent.h |   4 +-
 .../Libraries/LibWeb/HTML/MessagePort.cpp     |   6 +-
 Userland/Libraries/LibWeb/HTML/MessagePort.h  |   2 +-
 Userland/Libraries/LibWeb/HTML/Navigator.cpp  |  12 +-
 Userland/Libraries/LibWeb/HTML/Navigator.h    |   6 +-
 .../LibWeb/HTML/PageTransitionEvent.cpp       |   4 +-
 .../LibWeb/HTML/PageTransitionEvent.h         |   4 +-
 .../HTML/Parser/HTMLEncodingDetection.cpp     |  10 +-
 .../LibWeb/HTML/Parser/HTMLParser.cpp         |  24 +-
 Userland/Libraries/LibWeb/HTML/Path2D.cpp     |   2 +-
 .../LibWeb/HTML/PromiseRejectionEvent.cpp     |   4 +-
 .../LibWeb/HTML/PromiseRejectionEvent.h       |   4 +-
 .../LibWeb/HTML/Scripting/Environments.cpp    |   2 +-
 .../LibWeb/HTML/Scripting/ModuleScript.cpp    |   2 +-
 .../WindowEnvironmentSettingsObject.cpp       |  10 +-
 .../WindowEnvironmentSettingsObject.h         |   2 +-
 .../WorkerEnvironmentSettingsObject.h         |   4 +-
 Userland/Libraries/LibWeb/HTML/Storage.cpp    |   4 +-
 Userland/Libraries/LibWeb/HTML/Storage.h      |   2 +-
 .../LibWeb/HTML/StructuredSerialize.cpp       |   2 +-
 .../Libraries/LibWeb/HTML/SubmitEvent.cpp     |   4 +-
 Userland/Libraries/LibWeb/HTML/SubmitEvent.h  |   2 +-
 .../Libraries/LibWeb/HTML/TextMetrics.cpp     |   4 +-
 Userland/Libraries/LibWeb/HTML/TextMetrics.h  |   2 +-
 Userland/Libraries/LibWeb/HTML/TrackEvent.cpp |   4 +-
 Userland/Libraries/LibWeb/HTML/TrackEvent.h   |   4 +-
 Userland/Libraries/LibWeb/HTML/VideoTrack.cpp |   2 +-
 Userland/Libraries/LibWeb/HTML/Window.cpp     |  84 +++---
 Userland/Libraries/LibWeb/HTML/Window.h       |  18 +-
 Userland/Libraries/LibWeb/HTML/Worker.cpp     |  10 +-
 .../LibWeb/HTML/WorkerGlobalScope.cpp         |   2 +-
 .../Libraries/LibWeb/HTML/WorkerNavigator.cpp |   4 +-
 .../Libraries/LibWeb/HTML/WorkerNavigator.h   |   2 +-
 .../LibWeb/HighResolutionTime/Performance.cpp |   4 +-
 .../IntersectionObserver.cpp                  |   2 +-
 .../IntersectionObserverEntry.cpp             |   8 +-
 .../Libraries/LibWeb/Layout/TreeBuilder.cpp   |   2 +-
 .../Libraries/LibWeb/MathML/MathMLElement.cpp |   2 +-
 .../Libraries/LibWeb/Page/EventHandler.cpp    |   4 +-
 .../RequestIdleCallback/IdleDeadline.cpp      |   4 +-
 .../LibWeb/RequestIdleCallback/IdleDeadline.h |   2 +-
 .../LibWeb/ResizeObserver/ResizeObserver.cpp  |   2 +-
 .../LibWeb/SVG/SVGAnimatedLength.cpp          |   4 +-
 .../Libraries/LibWeb/SVG/SVGAnimatedLength.h  |   2 +-
 .../LibWeb/SVG/SVGAnimatedNumber.cpp          |   4 +-
 .../Libraries/LibWeb/SVG/SVGAnimatedNumber.h  |   2 +-
 .../Libraries/LibWeb/SVG/SVGCircleElement.cpp |  18 +-
 Userland/Libraries/LibWeb/SVG/SVGElement.cpp  |   2 +-
 .../LibWeb/SVG/SVGEllipseElement.cpp          |  24 +-
 .../LibWeb/SVG/SVGForeignObjectElement.cpp    |   8 +-
 Userland/Libraries/LibWeb/SVG/SVGLength.cpp   |   4 +-
 Userland/Libraries/LibWeb/SVG/SVGLength.h     |   2 +-
 .../Libraries/LibWeb/SVG/SVGLineElement.cpp   |  24 +-
 .../Libraries/LibWeb/SVG/SVGRectElement.cpp   |  36 +--
 .../Libraries/LibWeb/SVG/SVGUseElement.cpp    |  16 +-
 .../Libraries/LibWeb/Selection/Selection.cpp  |  16 +-
 .../Libraries/LibWeb/Selection/Selection.h    |   2 +-
 .../LibWeb/Streams/AbstractOperations.cpp     |  26 +-
 .../Streams/ByteLengthQueuingStrategy.cpp     |   2 +-
 .../LibWeb/Streams/CountQueuingStrategy.cpp   |   2 +-
 .../LibWeb/Streams/ReadableStream.cpp         |   2 +-
 .../Streams/ReadableStreamDefaultReader.cpp   |   2 +-
 .../LibWeb/Streams/TransformStream.cpp        |   2 +-
 .../LibWeb/Streams/WritableStream.cpp         |   2 +-
 .../Streams/WritableStreamDefaultWriter.cpp   |   2 +-
 .../Libraries/LibWeb/UIEvents/FocusEvent.cpp  |   2 +-
 .../LibWeb/UIEvents/KeyboardEvent.cpp         |  12 +-
 .../Libraries/LibWeb/UIEvents/KeyboardEvent.h |   6 +-
 .../Libraries/LibWeb/UIEvents/MouseEvent.cpp  |   4 +-
 .../Libraries/LibWeb/UIEvents/MouseEvent.h    |   2 +-
 .../Libraries/LibWeb/UIEvents/UIEvent.cpp     |   6 +-
 Userland/Libraries/LibWeb/UIEvents/UIEvent.h  |   2 +-
 .../Libraries/LibWeb/UIEvents/WheelEvent.cpp  |   4 +-
 .../Libraries/LibWeb/UIEvents/WheelEvent.h    |   2 +-
 Userland/Libraries/LibWeb/URL/URL.cpp         |   6 +-
 Userland/Libraries/LibWeb/URL/URL.h           |   2 +-
 .../Libraries/LibWeb/URL/URLSearchParams.cpp  |   2 +-
 .../LibWeb/URL/URLSearchParamsIterator.cpp    |   4 +-
 .../LibWeb/UserTiming/PerformanceMark.cpp     |   2 +-
 .../LibWeb/UserTiming/PerformanceMeasure.cpp  |   4 +-
 .../LibWeb/UserTiming/PerformanceMeasure.h    |   2 +-
 .../Libraries/LibWeb/WebAssembly/Instance.cpp |   6 +-
 .../Libraries/LibWeb/WebAssembly/Memory.cpp   |   2 +-
 .../Libraries/LibWeb/WebAssembly/Module.cpp   |   2 +-
 .../Libraries/LibWeb/WebAssembly/Table.cpp    |   2 +-
 .../LibWeb/WebAssembly/WebAssembly.cpp        |  10 +-
 .../LibWeb/WebAudio/AudioContext.cpp          |  10 +-
 .../LibWeb/WebGL/WebGLContextEvent.cpp        |   4 +-
 .../LibWeb/WebGL/WebGLContextEvent.h          |   4 +-
 .../LibWeb/WebGL/WebGLRenderingContext.cpp    |   4 +-
 .../Libraries/LibWeb/WebIDL/DOMException.cpp  |   4 +-
 .../Libraries/LibWeb/WebSockets/WebSocket.cpp |  12 +-
 Userland/Libraries/LibWeb/XHR/FormData.cpp    |   2 +-
 .../Libraries/LibWeb/XHR/FormDataIterator.cpp |   6 +-
 .../Libraries/LibWeb/XHR/FormDataIterator.h   |   2 +-
 .../Libraries/LibWeb/XHR/ProgressEvent.cpp    |   4 +-
 Userland/Libraries/LibWeb/XHR/ProgressEvent.h |   2 +-
 .../Libraries/LibWeb/XHR/XMLHttpRequest.cpp   |  18 +-
 .../LibWeb/XML/XMLDocumentBuilder.cpp         |   4 +-
 .../WebContent/WebContentConsoleClient.cpp    |   2 +-
 .../WebContent/WebDriverConnection.cpp        |   2 +-
 337 files changed, 1229 insertions(+), 1251 deletions(-)

diff --git a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
index dc4e2afd01b..ca175163ee3 100644
--- a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
@@ -3473,7 +3473,7 @@ JS::ThrowCompletionOr<JS::NonnullGCPtr<JS::Object>> @constructor_class@::constru
         // 3. Set element's namespace to the HTML namespace.
         // 4. Set element's namespace prefix to null.
         // 5. Set element's local name to definition's local name.
-        auto element = realm.heap().allocate<@fully_qualified_name@>(realm, window.associated_document(), DOM::QualifiedName { definition->local_name().to_deprecated_string(), {}, Namespace::HTML }).release_allocated_value_but_fixme_should_propagate_errors();
+        auto element = realm.heap().allocate<@fully_qualified_name@>(realm, window.associated_document(), DOM::QualifiedName { definition->local_name().to_deprecated_string(), {}, Namespace::HTML });
 
         // https://webidl.spec.whatwg.org/#internally-create-a-new-object-implementing-the-interface
         // Important steps from "internally create a new object implementing the interface"
diff --git a/Meta/Lagom/Tools/CodeGenerators/LibWeb/GenerateWindowOrWorkerInterfaces.cpp b/Meta/Lagom/Tools/CodeGenerators/LibWeb/GenerateWindowOrWorkerInterfaces.cpp
index 52441b9619f..98b66f2d710 100644
--- a/Meta/Lagom/Tools/CodeGenerators/LibWeb/GenerateWindowOrWorkerInterfaces.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/LibWeb/GenerateWindowOrWorkerInterfaces.cpp
@@ -157,7 +157,7 @@ namespace Web::Bindings {
 template<>
 void Intrinsics::create_web_namespace<@namespace_class@>(JS::Realm& realm)
 {
-    auto namespace_object = heap().allocate<@namespace_class@>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    auto namespace_object = heap().allocate<@namespace_class@>(realm, realm);
     m_namespaces.set("@interface_name@"sv, namespace_object);
 
     [[maybe_unused]] static constexpr u8 attr = JS::Attribute::Writable | JS::Attribute::Configurable;)~~~");
@@ -189,10 +189,10 @@ void Intrinsics::create_web_prototype_and_constructor<@prototype_class@>(JS::Rea
 {
     auto& vm = realm.vm();
 
-    auto prototype = heap().allocate<@prototype_class@>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    auto prototype = heap().allocate<@prototype_class@>(realm, realm);
     m_prototypes.set("@interface_name@"sv, prototype);
 
-    auto constructor = heap().allocate<@constructor_class@>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    auto constructor = heap().allocate<@constructor_class@>(realm, realm);
     m_constructors.set("@interface_name@"sv, constructor);
 
     prototype->define_direct_property(vm.names.constructor, constructor.ptr(), JS::Attribute::Writable | JS::Attribute::Configurable);
@@ -203,7 +203,7 @@ void Intrinsics::create_web_prototype_and_constructor<@prototype_class@>(JS::Rea
             gen.set("legacy_interface_name", legacy_constructor->name);
             gen.set("legacy_constructor_class", legacy_constructor->constructor_class);
             gen.append(R"~~~(
-    auto legacy_constructor = heap().allocate<@legacy_constructor_class@>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    auto legacy_constructor = heap().allocate<@legacy_constructor_class@>(realm, realm);
     m_constructors.set("@legacy_interface_name@"sv, legacy_constructor);
 
     legacy_constructor->define_direct_property(vm.names.name, JS::PrimitiveString::create(vm, "@legacy_interface_name@"_string), JS::Attribute::Configurable);)~~~");
diff --git a/Tests/LibWasm/test-wasm.cpp b/Tests/LibWasm/test-wasm.cpp
index 4466309c083..fe63f67b2d1 100644
--- a/Tests/LibWasm/test-wasm.cpp
+++ b/Tests/LibWasm/test-wasm.cpp
@@ -56,7 +56,7 @@ public:
     static JS::ThrowCompletionOr<WebAssemblyModule*> create(JS::Realm& realm, Wasm::Module module, HashMap<Wasm::Linker::Name, Wasm::ExternValue> const& imports)
     {
         auto& vm = realm.vm();
-        auto instance = MUST_OR_THROW_OOM(realm.heap().allocate<WebAssemblyModule>(realm, realm.intrinsics().object_prototype()));
+        auto instance = realm.heap().allocate<WebAssemblyModule>(realm, realm.intrinsics().object_prototype());
         instance->m_module = move(module);
         Wasm::Linker linker(*instance->m_module);
         linker.link(imports);
diff --git a/Userland/Applications/Spreadsheet/Workbook.cpp b/Userland/Applications/Spreadsheet/Workbook.cpp
index 4e62247de64..ec53f159693 100644
--- a/Userland/Applications/Spreadsheet/Workbook.cpp
+++ b/Userland/Applications/Spreadsheet/Workbook.cpp
@@ -28,7 +28,7 @@ Workbook::Workbook(Vector<NonnullRefPtr<Sheet>>&& sheets, GUI::Window& parent_wi
 {
     auto& realm = *m_root_execution_context->realm;
     auto& vm = realm.vm();
-    m_workbook_object = vm.heap().allocate<WorkbookObject>(realm, realm, *this).release_allocated_value_but_fixme_should_propagate_errors();
+    m_workbook_object = vm.heap().allocate<WorkbookObject>(realm, realm, *this);
     realm.global_object().define_direct_property("workbook", workbook_object(), JS::default_attributes);
 
     m_main_execution_context.this_value = &realm.global_object();
diff --git a/Userland/Libraries/LibJS/Contrib/Test262/262Object.cpp b/Userland/Libraries/LibJS/Contrib/Test262/262Object.cpp
index c07bce1c370..d39a277560a 100644
--- a/Userland/Libraries/LibJS/Contrib/Test262/262Object.cpp
+++ b/Userland/Libraries/LibJS/Contrib/Test262/262Object.cpp
@@ -30,8 +30,8 @@ void $262Object::initialize(Realm& realm)
 {
     Base::initialize(realm);
 
-    m_agent = MUST(vm().heap().allocate<AgentObject>(realm, realm));
-    m_is_htmldda = MUST(vm().heap().allocate<IsHTMLDDA>(realm, realm));
+    m_agent = vm().heap().allocate<AgentObject>(realm, realm);
+    m_is_htmldda = vm().heap().allocate<IsHTMLDDA>(realm, realm);
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(realm, "clearKeptObjects", clear_kept_objects, 0, attr);
diff --git a/Userland/Libraries/LibJS/Contrib/Test262/GlobalObject.cpp b/Userland/Libraries/LibJS/Contrib/Test262/GlobalObject.cpp
index 87be56cf3dc..3741b2671c2 100644
--- a/Userland/Libraries/LibJS/Contrib/Test262/GlobalObject.cpp
+++ b/Userland/Libraries/LibJS/Contrib/Test262/GlobalObject.cpp
@@ -18,7 +18,7 @@ void GlobalObject::initialize(Realm& realm)
 {
     Base::initialize(realm);
 
-    m_$262 = MUST(vm().heap().allocate<$262Object>(realm, realm));
+    m_$262 = vm().heap().allocate<$262Object>(realm, realm);
 
     // https://github.com/tc39/test262/blob/master/INTERPRETING.md#host-defined-functions
     u8 attr = Attribute::Writable | Attribute::Configurable;
diff --git a/Userland/Libraries/LibJS/Heap/Heap.h b/Userland/Libraries/LibJS/Heap/Heap.h
index 807347b5b75..657e1958160 100644
--- a/Userland/Libraries/LibJS/Heap/Heap.h
+++ b/Userland/Libraries/LibJS/Heap/Heap.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2020-2023, Andreas Kling <kling@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -43,7 +43,7 @@ public:
     }
 
     template<typename T, typename... Args>
-    ThrowCompletionOr<NonnullGCPtr<T>> allocate(Realm& realm, Args&&... args)
+    NonnullGCPtr<T> allocate(Realm& realm, Args&&... args)
     {
         auto* memory = allocate_cell(sizeof(T));
         new (memory) T(forward<Args>(args)...);
diff --git a/Userland/Libraries/LibJS/Module.cpp b/Userland/Libraries/LibJS/Module.cpp
index 714a8d15e89..38ad302488f 100644
--- a/Userland/Libraries/LibJS/Module.cpp
+++ b/Userland/Libraries/LibJS/Module.cpp
@@ -114,7 +114,7 @@ Object* Module::module_namespace_create(VM& vm, Vector<DeprecatedFlyString> unam
     // 6. Let sortedExports be a List whose elements are the elements of exports ordered as if an Array of the same values had been sorted using %Array.prototype.sort% using undefined as comparefn.
     // 7. Set M.[[Exports]] to sortedExports.
     // 8. Create own properties of M corresponding to the definitions in 28.3.
-    auto module_namespace = vm.heap().allocate<ModuleNamespaceObject>(realm, realm, this, move(unambiguous_names)).release_allocated_value_but_fixme_should_propagate_errors();
+    auto module_namespace = vm.heap().allocate<ModuleNamespaceObject>(realm, realm, this, move(unambiguous_names));
 
     // 9. Set module.[[Namespace]] to M.
     m_namespace = make_handle(module_namespace);
diff --git a/Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp b/Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp
index 7bc12fea665..12aee23a268 100644
--- a/Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp
+++ b/Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp
@@ -1103,7 +1103,7 @@ Object* create_mapped_arguments_object(VM& vm, FunctionObject& function, Vector<
     // 7. Set obj.[[Set]] as specified in 10.4.4.4.
     // 8. Set obj.[[Delete]] as specified in 10.4.4.5.
     // 9. Set obj.[[Prototype]] to %Object.prototype%.
-    auto object = vm.heap().allocate<ArgumentsObject>(realm, realm, environment).release_allocated_value_but_fixme_should_propagate_errors();
+    auto object = vm.heap().allocate<ArgumentsObject>(realm, realm, environment);
 
     // 14. Let index be 0.
     // 15. Repeat, while index < len,
diff --git a/Userland/Libraries/LibJS/Runtime/AbstractOperations.h b/Userland/Libraries/LibJS/Runtime/AbstractOperations.h
index 2146fb4e02d..6be2d303d0e 100644
--- a/Userland/Libraries/LibJS/Runtime/AbstractOperations.h
+++ b/Userland/Libraries/LibJS/Runtime/AbstractOperations.h
@@ -149,7 +149,7 @@ ThrowCompletionOr<NonnullGCPtr<T>> ordinary_create_from_constructor(VM& vm, Func
 {
     auto& realm = *vm.current_realm();
     auto* prototype = TRY(get_prototype_from_constructor(vm, constructor, intrinsic_default_prototype));
-    return MUST_OR_THROW_OOM(realm.heap().allocate<T>(realm, forward<Args>(args)..., *prototype));
+    return realm.heap().allocate<T>(realm, forward<Args>(args)..., *prototype);
 }
 
 // 14.1 MergeLists ( a, b ), https://tc39.es/proposal-temporal/#sec-temporal-mergelists
diff --git a/Userland/Libraries/LibJS/Runtime/AggregateError.cpp b/Userland/Libraries/LibJS/Runtime/AggregateError.cpp
index ce73fdac7e2..b1b55bdbf43 100644
--- a/Userland/Libraries/LibJS/Runtime/AggregateError.cpp
+++ b/Userland/Libraries/LibJS/Runtime/AggregateError.cpp
@@ -12,7 +12,7 @@ namespace JS {
 
 NonnullGCPtr<AggregateError> AggregateError::create(Realm& realm)
 {
-    return realm.heap().allocate<AggregateError>(realm, realm.intrinsics().aggregate_error_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<AggregateError>(realm, realm.intrinsics().aggregate_error_prototype());
 }
 
 AggregateError::AggregateError(Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/Array.cpp b/Userland/Libraries/LibJS/Runtime/Array.cpp
index 204628bf17a..90d5ca057ce 100644
--- a/Userland/Libraries/LibJS/Runtime/Array.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Array.cpp
@@ -32,7 +32,7 @@ ThrowCompletionOr<NonnullGCPtr<Array>> Array::create(Realm& realm, u64 length, O
     // 3. Let A be MakeBasicObject(« [[Prototype]], [[Extensible]] »).
     // 4. Set A.[[Prototype]] to proto.
     // 5. Set A.[[DefineOwnProperty]] as specified in 10.4.2.1.
-    auto array = MUST_OR_THROW_OOM(realm.heap().allocate<Array>(realm, *prototype));
+    auto array = realm.heap().allocate<Array>(realm, *prototype);
 
     // 6. Perform ! OrdinaryDefineOwnProperty(A, "length", PropertyDescriptor { [[Value]]: 𝔽(length), [[Writable]]: true, [[Enumerable]]: false, [[Configurable]]: false }).
     MUST(array->internal_define_own_property(vm.names.length, { .value = Value(length), .writable = true, .enumerable = false, .configurable = false }));
diff --git a/Userland/Libraries/LibJS/Runtime/ArrayBuffer.cpp b/Userland/Libraries/LibJS/Runtime/ArrayBuffer.cpp
index bd4b3c5065f..8e3ef6eff8b 100644
--- a/Userland/Libraries/LibJS/Runtime/ArrayBuffer.cpp
+++ b/Userland/Libraries/LibJS/Runtime/ArrayBuffer.cpp
@@ -17,17 +17,17 @@ ThrowCompletionOr<NonnullGCPtr<ArrayBuffer>> ArrayBuffer::create(Realm& realm, s
     if (buffer.is_error())
         return realm.vm().throw_completion<RangeError>(ErrorType::NotEnoughMemoryToAllocate, byte_length);
 
-    return MUST_OR_THROW_OOM(realm.heap().allocate<ArrayBuffer>(realm, buffer.release_value(), realm.intrinsics().array_buffer_prototype()));
+    return realm.heap().allocate<ArrayBuffer>(realm, buffer.release_value(), realm.intrinsics().array_buffer_prototype());
 }
 
 NonnullGCPtr<ArrayBuffer> ArrayBuffer::create(Realm& realm, ByteBuffer buffer)
 {
-    return realm.heap().allocate<ArrayBuffer>(realm, move(buffer), realm.intrinsics().array_buffer_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<ArrayBuffer>(realm, move(buffer), realm.intrinsics().array_buffer_prototype());
 }
 
 NonnullGCPtr<ArrayBuffer> ArrayBuffer::create(Realm& realm, ByteBuffer* buffer)
 {
-    return realm.heap().allocate<ArrayBuffer>(realm, buffer, realm.intrinsics().array_buffer_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<ArrayBuffer>(realm, buffer, realm.intrinsics().array_buffer_prototype());
 }
 
 ArrayBuffer::ArrayBuffer(ByteBuffer buffer, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/ArrayIterator.cpp b/Userland/Libraries/LibJS/Runtime/ArrayIterator.cpp
index 662a679667a..e2d5ac99807 100644
--- a/Userland/Libraries/LibJS/Runtime/ArrayIterator.cpp
+++ b/Userland/Libraries/LibJS/Runtime/ArrayIterator.cpp
@@ -11,7 +11,7 @@ namespace JS {
 
 NonnullGCPtr<ArrayIterator> ArrayIterator::create(Realm& realm, Value array, Object::PropertyKind iteration_kind)
 {
-    return realm.heap().allocate<ArrayIterator>(realm, array, iteration_kind, realm.intrinsics().array_iterator_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<ArrayIterator>(realm, array, iteration_kind, realm.intrinsics().array_iterator_prototype());
 }
 
 ArrayIterator::ArrayIterator(Value array, Object::PropertyKind iteration_kind, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/AsyncFromSyncIterator.cpp b/Userland/Libraries/LibJS/Runtime/AsyncFromSyncIterator.cpp
index a28fe0f908e..ab18c3ce70b 100644
--- a/Userland/Libraries/LibJS/Runtime/AsyncFromSyncIterator.cpp
+++ b/Userland/Libraries/LibJS/Runtime/AsyncFromSyncIterator.cpp
@@ -13,7 +13,7 @@ namespace JS {
 
 NonnullGCPtr<AsyncFromSyncIterator> AsyncFromSyncIterator::create(Realm& realm, IteratorRecord sync_iterator_record)
 {
-    return realm.heap().allocate<AsyncFromSyncIterator>(realm, realm, sync_iterator_record).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<AsyncFromSyncIterator>(realm, realm, sync_iterator_record);
 }
 
 AsyncFromSyncIterator::AsyncFromSyncIterator(Realm& realm, IteratorRecord sync_iterator_record)
diff --git a/Userland/Libraries/LibJS/Runtime/AsyncFunctionDriverWrapper.cpp b/Userland/Libraries/LibJS/Runtime/AsyncFunctionDriverWrapper.cpp
index d718666e2ec..6daa34bf50d 100644
--- a/Userland/Libraries/LibJS/Runtime/AsyncFunctionDriverWrapper.cpp
+++ b/Userland/Libraries/LibJS/Runtime/AsyncFunctionDriverWrapper.cpp
@@ -14,12 +14,12 @@
 
 namespace JS {
 
-ThrowCompletionOr<Value> AsyncFunctionDriverWrapper::create(Realm& realm, GeneratorObject* generator_object)
+NonnullGCPtr<Promise> AsyncFunctionDriverWrapper::create(Realm& realm, GeneratorObject* generator_object)
 {
     auto top_level_promise = Promise::create(realm);
     // Note: This generates a handle to itself, which it clears upon completing its execution
     //       The top_level_promise is also kept alive by this Wrapper
-    auto wrapper = MUST_OR_THROW_OOM(realm.heap().allocate<AsyncFunctionDriverWrapper>(realm, realm, *generator_object, *top_level_promise));
+    auto wrapper = realm.heap().allocate<AsyncFunctionDriverWrapper>(realm, realm, *generator_object, *top_level_promise);
     // Prime the generator:
     // This runs until the first `await value;`
     wrapper->continue_async_execution(realm.vm(), js_undefined(), true, IsInitialExecution::Yes);
diff --git a/Userland/Libraries/LibJS/Runtime/AsyncFunctionDriverWrapper.h b/Userland/Libraries/LibJS/Runtime/AsyncFunctionDriverWrapper.h
index 7f3fd385146..5ddcd86ec0a 100644
--- a/Userland/Libraries/LibJS/Runtime/AsyncFunctionDriverWrapper.h
+++ b/Userland/Libraries/LibJS/Runtime/AsyncFunctionDriverWrapper.h
@@ -23,7 +23,7 @@ public:
         Yes,
     };
 
-    static ThrowCompletionOr<Value> create(Realm&, GeneratorObject*);
+    [[nodiscard]] static NonnullGCPtr<Promise> create(Realm&, GeneratorObject*);
 
     virtual ~AsyncFunctionDriverWrapper() override = default;
     void visit_edges(Cell::Visitor&) override;
diff --git a/Userland/Libraries/LibJS/Runtime/AsyncGenerator.cpp b/Userland/Libraries/LibJS/Runtime/AsyncGenerator.cpp
index 178fdde7033..58f8aa7f86e 100644
--- a/Userland/Libraries/LibJS/Runtime/AsyncGenerator.cpp
+++ b/Userland/Libraries/LibJS/Runtime/AsyncGenerator.cpp
@@ -20,7 +20,7 @@ ThrowCompletionOr<NonnullGCPtr<AsyncGenerator>> AsyncGenerator::create(Realm& re
     // This is "g1.prototype" in figure-2 (https://tc39.es/ecma262/img/figure-2.png)
     auto generating_function_prototype = TRY(generating_function->get(vm.names.prototype));
     auto generating_function_prototype_object = TRY(generating_function_prototype.to_object(vm));
-    auto object = MUST_OR_THROW_OOM(realm.heap().allocate<AsyncGenerator>(realm, realm, generating_function_prototype_object, move(execution_context)));
+    auto object = realm.heap().allocate<AsyncGenerator>(realm, realm, generating_function_prototype_object, move(execution_context));
     object->m_generating_function = generating_function;
     object->m_frame = move(frame);
     object->m_previous_value = initial_value;
diff --git a/Userland/Libraries/LibJS/Runtime/BigIntObject.cpp b/Userland/Libraries/LibJS/Runtime/BigIntObject.cpp
index bdb946df7ad..c0e7b739341 100644
--- a/Userland/Libraries/LibJS/Runtime/BigIntObject.cpp
+++ b/Userland/Libraries/LibJS/Runtime/BigIntObject.cpp
@@ -11,7 +11,7 @@ namespace JS {
 
 NonnullGCPtr<BigIntObject> BigIntObject::create(Realm& realm, BigInt& bigint)
 {
-    return realm.heap().allocate<BigIntObject>(realm, bigint, realm.intrinsics().bigint_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<BigIntObject>(realm, bigint, realm.intrinsics().bigint_prototype());
 }
 
 BigIntObject::BigIntObject(BigInt& bigint, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/BooleanObject.cpp b/Userland/Libraries/LibJS/Runtime/BooleanObject.cpp
index edf2262a3ac..37d9f0ca80c 100644
--- a/Userland/Libraries/LibJS/Runtime/BooleanObject.cpp
+++ b/Userland/Libraries/LibJS/Runtime/BooleanObject.cpp
@@ -11,7 +11,7 @@ namespace JS {
 
 NonnullGCPtr<BooleanObject> BooleanObject::create(Realm& realm, bool value)
 {
-    return realm.heap().allocate<BooleanObject>(realm, value, realm.intrinsics().boolean_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<BooleanObject>(realm, value, realm.intrinsics().boolean_prototype());
 }
 
 BooleanObject::BooleanObject(bool value, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/BoundFunction.cpp b/Userland/Libraries/LibJS/Runtime/BoundFunction.cpp
index 6c0bc8d7cbf..82e34d745fa 100644
--- a/Userland/Libraries/LibJS/Runtime/BoundFunction.cpp
+++ b/Userland/Libraries/LibJS/Runtime/BoundFunction.cpp
@@ -26,7 +26,7 @@ ThrowCompletionOr<NonnullGCPtr<BoundFunction>> BoundFunction::create(Realm& real
     // 7. Set obj.[[BoundTargetFunction]] to targetFunction.
     // 8. Set obj.[[BoundThis]] to boundThis.
     // 9. Set obj.[[BoundArguments]] to boundArgs.
-    auto object = MUST_OR_THROW_OOM(realm.heap().allocate<BoundFunction>(realm, realm, target_function, bound_this, move(bound_arguments), prototype));
+    auto object = realm.heap().allocate<BoundFunction>(realm, realm, target_function, bound_this, move(bound_arguments), prototype);
 
     // 10. Return obj.
     return object;
diff --git a/Userland/Libraries/LibJS/Runtime/DataView.cpp b/Userland/Libraries/LibJS/Runtime/DataView.cpp
index 6249eb9dcda..905e553772e 100644
--- a/Userland/Libraries/LibJS/Runtime/DataView.cpp
+++ b/Userland/Libraries/LibJS/Runtime/DataView.cpp
@@ -10,7 +10,7 @@ namespace JS {
 
 NonnullGCPtr<DataView> DataView::create(Realm& realm, ArrayBuffer* viewed_buffer, size_t byte_length, size_t byte_offset)
 {
-    return realm.heap().allocate<DataView>(realm, viewed_buffer, byte_length, byte_offset, realm.intrinsics().data_view_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<DataView>(realm, viewed_buffer, byte_length, byte_offset, realm.intrinsics().data_view_prototype());
 }
 
 DataView::DataView(ArrayBuffer* viewed_buffer, size_t byte_length, size_t byte_offset, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/Date.cpp b/Userland/Libraries/LibJS/Runtime/Date.cpp
index c64e61b40f1..655c57b105e 100644
--- a/Userland/Libraries/LibJS/Runtime/Date.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Date.cpp
@@ -25,7 +25,7 @@ Crypto::SignedBigInteger const ns_per_day_bigint { static_cast<i64>(ns_per_day)
 
 NonnullGCPtr<Date> Date::create(Realm& realm, double date_value)
 {
-    return realm.heap().allocate<Date>(realm, date_value, realm.intrinsics().date_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<Date>(realm, date_value, realm.intrinsics().date_prototype());
 }
 
 Date::Date(double date_value, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp b/Userland/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp
index 670fa03ab91..e3867e11db3 100644
--- a/Userland/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp
+++ b/Userland/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp
@@ -48,12 +48,12 @@ NonnullGCPtr<ECMAScriptFunctionObject> ECMAScriptFunctionObject::create(Realm& r
         prototype = realm.intrinsics().async_generator_function_prototype();
         break;
     }
-    return realm.heap().allocate<ECMAScriptFunctionObject>(realm, move(name), move(source_text), ecmascript_code, move(parameters), m_function_length, move(local_variables_names), parent_environment, private_environment, *prototype, kind, is_strict, might_need_arguments_object, contains_direct_call_to_eval, is_arrow_function, move(class_field_initializer_name)).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<ECMAScriptFunctionObject>(realm, move(name), move(source_text), ecmascript_code, move(parameters), m_function_length, move(local_variables_names), parent_environment, private_environment, *prototype, kind, is_strict, might_need_arguments_object, contains_direct_call_to_eval, is_arrow_function, move(class_field_initializer_name));
 }
 
 NonnullGCPtr<ECMAScriptFunctionObject> ECMAScriptFunctionObject::create(Realm& realm, DeprecatedFlyString name, Object& prototype, DeprecatedString source_text, Statement const& ecmascript_code, Vector<FunctionParameter> parameters, i32 m_function_length, Vector<DeprecatedFlyString> local_variables_names, Environment* parent_environment, PrivateEnvironment* private_environment, FunctionKind kind, bool is_strict, bool might_need_arguments_object, bool contains_direct_call_to_eval, bool is_arrow_function, Variant<PropertyKey, PrivateName, Empty> class_field_initializer_name)
 {
-    return realm.heap().allocate<ECMAScriptFunctionObject>(realm, move(name), move(source_text), ecmascript_code, move(parameters), m_function_length, move(local_variables_names), parent_environment, private_environment, prototype, kind, is_strict, might_need_arguments_object, contains_direct_call_to_eval, is_arrow_function, move(class_field_initializer_name)).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<ECMAScriptFunctionObject>(realm, move(name), move(source_text), ecmascript_code, move(parameters), m_function_length, move(local_variables_names), parent_environment, private_environment, prototype, kind, is_strict, might_need_arguments_object, contains_direct_call_to_eval, is_arrow_function, move(class_field_initializer_name));
 }
 
 ECMAScriptFunctionObject::ECMAScriptFunctionObject(DeprecatedFlyString name, DeprecatedString source_text, Statement const& ecmascript_code, Vector<FunctionParameter> formal_parameters, i32 function_length, Vector<DeprecatedFlyString> local_variables_names, Environment* parent_environment, PrivateEnvironment* private_environment, Object& prototype, FunctionKind kind, bool strict, bool might_need_arguments_object, bool contains_direct_call_to_eval, bool is_arrow_function, Variant<PropertyKey, PrivateName, Empty> class_field_initializer_name)
@@ -118,7 +118,7 @@ void ECMAScriptFunctionObject::initialize(Realm& realm)
         Object* prototype = nullptr;
         switch (m_kind) {
         case FunctionKind::Normal:
-            prototype = MUST(vm.heap().allocate<Object>(realm, realm.intrinsics().new_ordinary_function_prototype_object_shape()));
+            prototype = vm.heap().allocate<Object>(realm, realm.intrinsics().new_ordinary_function_prototype_object_shape());
             MUST(prototype->define_property_or_throw(vm.names.constructor, { .value = this, .writable = true, .enumerable = false, .configurable = true }));
             break;
         case FunctionKind::Generator:
@@ -1088,7 +1088,7 @@ Completion ECMAScriptFunctionObject::ordinary_call_evaluate_body()
     // NOTE: Async functions are entirely transformed to generator functions, and wrapped in a custom driver that returns a promise
     //       See AwaitExpression::generate_bytecode() for the transformation.
     if (m_kind == FunctionKind::Async)
-        return { Completion::Type::Return, TRY(AsyncFunctionDriverWrapper::create(realm, generator_object)), {} };
+        return { Completion::Type::Return, AsyncFunctionDriverWrapper::create(realm, generator_object), {} };
 
     VERIFY(m_kind == FunctionKind::Generator);
     return { Completion::Type::Return, generator_object, {} };
diff --git a/Userland/Libraries/LibJS/Runtime/Error.cpp b/Userland/Libraries/LibJS/Runtime/Error.cpp
index 1d43647d9c4..92795ccc274 100644
--- a/Userland/Libraries/LibJS/Runtime/Error.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Error.cpp
@@ -32,7 +32,7 @@ SourceRange const& TracebackFrame::source_range() const
 
 NonnullGCPtr<Error> Error::create(Realm& realm)
 {
-    return realm.heap().allocate<Error>(realm, realm.intrinsics().error_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<Error>(realm, realm.intrinsics().error_prototype());
 }
 
 NonnullGCPtr<Error> Error::create(Realm& realm, String message)
@@ -119,29 +119,29 @@ ThrowCompletionOr<String> Error::stack_string(VM& vm) const
     return stack_string_builder.to_string();
 }
 
-#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName, ArrayType)                                                                         \
-    NonnullGCPtr<ClassName> ClassName::create(Realm& realm)                                                                                                      \
-    {                                                                                                                                                            \
-        return realm.heap().allocate<ClassName>(realm, realm.intrinsics().snake_name##_prototype()).release_allocated_value_but_fixme_should_propagate_errors(); \
-    }                                                                                                                                                            \
-                                                                                                                                                                 \
-    NonnullGCPtr<ClassName> ClassName::create(Realm& realm, String message)                                                                                      \
-    {                                                                                                                                                            \
-        auto& vm = realm.vm();                                                                                                                                   \
-        auto error = ClassName::create(realm);                                                                                                                   \
-        u8 attr = Attribute::Writable | Attribute::Configurable;                                                                                                 \
-        error->define_direct_property(vm.names.message, PrimitiveString::create(vm, move(message)), attr);                                                       \
-        return error;                                                                                                                                            \
-    }                                                                                                                                                            \
-                                                                                                                                                                 \
-    ThrowCompletionOr<NonnullGCPtr<ClassName>> ClassName::create(Realm& realm, StringView message)                                                               \
-    {                                                                                                                                                            \
-        return create(realm, TRY_OR_THROW_OOM(realm.vm(), String::from_utf8(message)));                                                                          \
-    }                                                                                                                                                            \
-                                                                                                                                                                 \
-    ClassName::ClassName(Object& prototype)                                                                                                                      \
-        : Error(prototype)                                                                                                                                       \
-    {                                                                                                                                                            \
+#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName, ArrayType)                   \
+    NonnullGCPtr<ClassName> ClassName::create(Realm& realm)                                                \
+    {                                                                                                      \
+        return realm.heap().allocate<ClassName>(realm, realm.intrinsics().snake_name##_prototype());       \
+    }                                                                                                      \
+                                                                                                           \
+    NonnullGCPtr<ClassName> ClassName::create(Realm& realm, String message)                                \
+    {                                                                                                      \
+        auto& vm = realm.vm();                                                                             \
+        auto error = ClassName::create(realm);                                                             \
+        u8 attr = Attribute::Writable | Attribute::Configurable;                                           \
+        error->define_direct_property(vm.names.message, PrimitiveString::create(vm, move(message)), attr); \
+        return error;                                                                                      \
+    }                                                                                                      \
+                                                                                                           \
+    ThrowCompletionOr<NonnullGCPtr<ClassName>> ClassName::create(Realm& realm, StringView message)         \
+    {                                                                                                      \
+        return create(realm, TRY_OR_THROW_OOM(realm.vm(), String::from_utf8(message)));                    \
+    }                                                                                                      \
+                                                                                                           \
+    ClassName::ClassName(Object& prototype)                                                                \
+        : Error(prototype)                                                                                 \
+    {                                                                                                      \
     }
 
 JS_ENUMERATE_NATIVE_ERRORS
diff --git a/Userland/Libraries/LibJS/Runtime/GeneratorObject.cpp b/Userland/Libraries/LibJS/Runtime/GeneratorObject.cpp
index 1c7fc6e9bf5..6dc17b279e8 100644
--- a/Userland/Libraries/LibJS/Runtime/GeneratorObject.cpp
+++ b/Userland/Libraries/LibJS/Runtime/GeneratorObject.cpp
@@ -28,7 +28,7 @@ ThrowCompletionOr<NonnullGCPtr<GeneratorObject>> GeneratorObject::create(Realm&
         generating_function_prototype = TRY(generating_function->get(vm.names.prototype));
     }
     auto generating_function_prototype_object = TRY(generating_function_prototype.to_object(vm));
-    auto object = MUST_OR_THROW_OOM(realm.heap().allocate<GeneratorObject>(realm, realm, generating_function_prototype_object, move(execution_context)));
+    auto object = realm.heap().allocate<GeneratorObject>(realm, realm, generating_function_prototype_object, move(execution_context));
     object->m_generating_function = generating_function;
     object->m_frame = move(frame);
     object->m_previous_value = initial_value;
diff --git a/Userland/Libraries/LibJS/Runtime/Intl/CollatorCompareFunction.cpp b/Userland/Libraries/LibJS/Runtime/Intl/CollatorCompareFunction.cpp
index ce573ff0570..52ed7123a69 100644
--- a/Userland/Libraries/LibJS/Runtime/Intl/CollatorCompareFunction.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Intl/CollatorCompareFunction.cpp
@@ -13,7 +13,7 @@ namespace JS::Intl {
 
 NonnullGCPtr<CollatorCompareFunction> CollatorCompareFunction::create(Realm& realm, Collator& collator)
 {
-    return realm.heap().allocate<CollatorCompareFunction>(realm, realm, collator).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<CollatorCompareFunction>(realm, realm, collator);
 }
 
 CollatorCompareFunction::CollatorCompareFunction(Realm& realm, Collator& collator)
diff --git a/Userland/Libraries/LibJS/Runtime/Intl/DateTimeFormatFunction.cpp b/Userland/Libraries/LibJS/Runtime/Intl/DateTimeFormatFunction.cpp
index 11e93ed387a..6eebeb635ba 100644
--- a/Userland/Libraries/LibJS/Runtime/Intl/DateTimeFormatFunction.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Intl/DateTimeFormatFunction.cpp
@@ -16,7 +16,7 @@ namespace JS::Intl {
 // 11.5.4 DateTime Format Functions, https://tc39.es/ecma402/#sec-datetime-format-functions
 NonnullGCPtr<DateTimeFormatFunction> DateTimeFormatFunction::create(Realm& realm, DateTimeFormat& date_time_format)
 {
-    return realm.heap().allocate<DateTimeFormatFunction>(realm, date_time_format, realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<DateTimeFormatFunction>(realm, date_time_format, realm.intrinsics().function_prototype());
 }
 
 DateTimeFormatFunction::DateTimeFormatFunction(DateTimeFormat& date_time_format, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/Intl/Locale.cpp b/Userland/Libraries/LibJS/Runtime/Intl/Locale.cpp
index 1e0ec597432..23b697baf3c 100644
--- a/Userland/Libraries/LibJS/Runtime/Intl/Locale.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Intl/Locale.cpp
@@ -16,7 +16,7 @@ namespace JS::Intl {
 
 ThrowCompletionOr<NonnullGCPtr<Locale>> Locale::create(Realm& realm, ::Locale::LocaleID locale_id)
 {
-    auto locale = MUST_OR_THROW_OOM(realm.heap().allocate<Locale>(realm, realm.intrinsics().intl_locale_prototype()));
+    auto locale = realm.heap().allocate<Locale>(realm, realm.intrinsics().intl_locale_prototype());
     locale->set_locale(TRY_OR_THROW_OOM(realm.vm(), locale_id.to_string()));
 
     for (auto& extension : locale_id.extensions) {
diff --git a/Userland/Libraries/LibJS/Runtime/Intl/NumberFormatFunction.cpp b/Userland/Libraries/LibJS/Runtime/Intl/NumberFormatFunction.cpp
index 16cfadb39fc..8e8e6433a30 100644
--- a/Userland/Libraries/LibJS/Runtime/Intl/NumberFormatFunction.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Intl/NumberFormatFunction.cpp
@@ -13,7 +13,7 @@ namespace JS::Intl {
 // 15.5.2 Number Format Functions, https://tc39.es/ecma402/#sec-number-format-functions
 NonnullGCPtr<NumberFormatFunction> NumberFormatFunction::create(Realm& realm, NumberFormat& number_format)
 {
-    return realm.heap().allocate<NumberFormatFunction>(realm, number_format, realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<NumberFormatFunction>(realm, number_format, realm.intrinsics().function_prototype());
 }
 
 NumberFormatFunction::NumberFormatFunction(NumberFormat& number_format, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/Intl/SegmentIterator.cpp b/Userland/Libraries/LibJS/Runtime/Intl/SegmentIterator.cpp
index 756293f5803..9fd403db5d6 100644
--- a/Userland/Libraries/LibJS/Runtime/Intl/SegmentIterator.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Intl/SegmentIterator.cpp
@@ -19,7 +19,7 @@ NonnullGCPtr<SegmentIterator> SegmentIterator::create(Realm& realm, Segmenter& s
     // 4. Set iterator.[[IteratedString]] to string.
     // 5. Set iterator.[[IteratedStringNextSegmentCodeUnitIndex]] to 0.
     // 6. Return iterator.
-    return realm.heap().allocate<SegmentIterator>(realm, realm, segmenter, move(string), segments).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<SegmentIterator>(realm, realm, segmenter, move(string), segments);
 }
 
 // 18.6 Segment Iterator Objects, https://tc39.es/ecma402/#sec-segment-iterator-objects
diff --git a/Userland/Libraries/LibJS/Runtime/Intl/Segments.cpp b/Userland/Libraries/LibJS/Runtime/Intl/Segments.cpp
index e6d1cf98199..b62e99f0948 100644
--- a/Userland/Libraries/LibJS/Runtime/Intl/Segments.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Intl/Segments.cpp
@@ -18,7 +18,7 @@ NonnullGCPtr<Segments> Segments::create(Realm& realm, Segmenter& segmenter, Utf1
     // 3. Set segments.[[SegmentsSegmenter]] to segmenter.
     // 4. Set segments.[[SegmentsString]] to string.
     // 5. Return segments.
-    return realm.heap().allocate<Segments>(realm, realm, segmenter, move(string)).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<Segments>(realm, realm, segmenter, move(string));
 }
 
 // 18.5 Segments Objects, https://tc39.es/ecma402/#sec-segments-objects
diff --git a/Userland/Libraries/LibJS/Runtime/Intrinsics.cpp b/Userland/Libraries/LibJS/Runtime/Intrinsics.cpp
index 48a603066d9..40502e234ca 100644
--- a/Userland/Libraries/LibJS/Runtime/Intrinsics.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Intrinsics.cpp
@@ -194,27 +194,27 @@ ThrowCompletionOr<void> Intrinsics::initialize_intrinsics(Realm& realm)
 
 #define __JS_ENUMERATE(ClassName, snake_name) \
     VERIFY(!m_##snake_name##_prototype);      \
-    m_##snake_name##_prototype = heap().allocate<ClassName##Prototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    m_##snake_name##_prototype = heap().allocate<ClassName##Prototype>(realm, realm);
     JS_ENUMERATE_ITERATOR_PROTOTYPES
 #undef __JS_ENUMERATE
 
     // These must be initialized separately as they have no companion constructor
-    m_async_from_sync_iterator_prototype = heap().allocate<AsyncFromSyncIteratorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
-    m_async_generator_prototype = heap().allocate<AsyncGeneratorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
-    m_generator_prototype = heap().allocate<GeneratorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
-    m_intl_segments_prototype = heap().allocate<Intl::SegmentsPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
-    m_wrap_for_valid_iterator_prototype = heap().allocate<WrapForValidIteratorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    m_async_from_sync_iterator_prototype = heap().allocate<AsyncFromSyncIteratorPrototype>(realm, realm);
+    m_async_generator_prototype = heap().allocate<AsyncGeneratorPrototype>(realm, realm);
+    m_generator_prototype = heap().allocate<GeneratorPrototype>(realm, realm);
+    m_intl_segments_prototype = heap().allocate<Intl::SegmentsPrototype>(realm, realm);
+    m_wrap_for_valid_iterator_prototype = heap().allocate<WrapForValidIteratorPrototype>(realm, realm);
 
     // These must be initialized before allocating...
     // - AggregateErrorPrototype, which uses ErrorPrototype as its prototype
     // - AggregateErrorConstructor, which uses ErrorConstructor as its prototype
     // - AsyncFunctionConstructor, which uses FunctionConstructor as its prototype
-    m_error_prototype = heap().allocate<ErrorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
-    m_error_constructor = heap().allocate<ErrorConstructor>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
-    m_function_constructor = heap().allocate<FunctionConstructor>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    m_error_prototype = heap().allocate<ErrorPrototype>(realm, realm);
+    m_error_constructor = heap().allocate<ErrorConstructor>(realm, realm);
+    m_function_constructor = heap().allocate<FunctionConstructor>(realm, realm);
 
     // Not included in JS_ENUMERATE_NATIVE_OBJECTS due to missing distinct prototype
-    m_proxy_constructor = heap().allocate<ProxyConstructor>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    m_proxy_constructor = heap().allocate<ProxyConstructor>(realm, realm);
 
     // Global object functions
     m_eval_function = NativeFunction::create(realm, GlobalObject::eval, 1, vm.names.eval, &realm);
@@ -229,7 +229,7 @@ ThrowCompletionOr<void> Intrinsics::initialize_intrinsics(Realm& realm)
     m_escape_function = NativeFunction::create(realm, GlobalObject::escape, 1, vm.names.escape, &realm);
     m_unescape_function = NativeFunction::create(realm, GlobalObject::unescape, 1, vm.names.unescape, &realm);
 
-    m_object_constructor = heap().allocate<ObjectConstructor>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    m_object_constructor = heap().allocate<ObjectConstructor>(realm, realm);
 
     // 10.2.4.1 %ThrowTypeError% ( ), https://tc39.es/ecma262/#sec-%throwtypeerror%
     m_throw_type_error_function = NativeFunction::create(
@@ -274,52 +274,52 @@ constexpr inline bool IsTypedArrayConstructor = false;
 JS_ENUMERATE_TYPED_ARRAYS
 #undef __JS_ENUMERATE
 
-#define __JS_ENUMERATE_INNER(ClassName, snake_name, PrototypeName, ConstructorName, Namespace, snake_namespace)                                                                                                    \
-    void Intrinsics::initialize_##snake_namespace##snake_name()                                                                                                                                                    \
-    {                                                                                                                                                                                                              \
-        auto& vm = this->vm();                                                                                                                                                                                     \
-                                                                                                                                                                                                                   \
-        VERIFY(!m_##snake_namespace##snake_name##_prototype);                                                                                                                                                      \
-        VERIFY(!m_##snake_namespace##snake_name##_constructor);                                                                                                                                                    \
-        if constexpr (IsTypedArrayConstructor<Namespace::ConstructorName>) {                                                                                                                                       \
-            m_##snake_namespace##snake_name##_prototype = heap().allocate<Namespace::PrototypeName>(m_realm, *typed_array_prototype()).release_allocated_value_but_fixme_should_propagate_errors();                \
-            m_##snake_namespace##snake_name##_constructor = heap().allocate<Namespace::ConstructorName>(m_realm, m_realm, *typed_array_constructor()).release_allocated_value_but_fixme_should_propagate_errors(); \
-        } else {                                                                                                                                                                                                   \
-            m_##snake_namespace##snake_name##_prototype = heap().allocate<Namespace::PrototypeName>(m_realm, m_realm).release_allocated_value_but_fixme_should_propagate_errors();                                 \
-            m_##snake_namespace##snake_name##_constructor = heap().allocate<Namespace::ConstructorName>(m_realm, m_realm).release_allocated_value_but_fixme_should_propagate_errors();                             \
-        }                                                                                                                                                                                                          \
-                                                                                                                                                                                                                   \
-        /* FIXME: Add these special cases to JS_ENUMERATE_NATIVE_OBJECTS */                                                                                                                                        \
-        if constexpr (IsSame<Namespace::ConstructorName, BigIntConstructor>)                                                                                                                                       \
-            initialize_constructor(vm, vm.names.BigInt, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                              \
-        else if constexpr (IsSame<Namespace::ConstructorName, BooleanConstructor>)                                                                                                                                 \
-            initialize_constructor(vm, vm.names.Boolean, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                             \
-        else if constexpr (IsSame<Namespace::ConstructorName, FunctionConstructor>)                                                                                                                                \
-            initialize_constructor(vm, vm.names.Function, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                            \
-        else if constexpr (IsSame<Namespace::ConstructorName, NumberConstructor>)                                                                                                                                  \
-            initialize_constructor(vm, vm.names.Number, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                              \
-        else if constexpr (IsSame<Namespace::ConstructorName, RegExpConstructor>)                                                                                                                                  \
-            initialize_constructor(vm, vm.names.RegExp, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                              \
-        else if constexpr (IsSame<Namespace::ConstructorName, StringConstructor>)                                                                                                                                  \
-            initialize_constructor(vm, vm.names.String, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                              \
-        else if constexpr (IsSame<Namespace::ConstructorName, SymbolConstructor>)                                                                                                                                  \
-            initialize_constructor(vm, vm.names.Symbol, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                              \
-        else                                                                                                                                                                                                       \
-            initialize_constructor(vm, vm.names.ClassName, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);                                                           \
-    }                                                                                                                                                                                                              \
-                                                                                                                                                                                                                   \
-    NonnullGCPtr<Namespace::ConstructorName> Intrinsics::snake_namespace##snake_name##_constructor()                                                                                                               \
-    {                                                                                                                                                                                                              \
-        if (!m_##snake_namespace##snake_name##_constructor)                                                                                                                                                        \
-            initialize_##snake_namespace##snake_name();                                                                                                                                                            \
-        return *m_##snake_namespace##snake_name##_constructor;                                                                                                                                                     \
-    }                                                                                                                                                                                                              \
-                                                                                                                                                                                                                   \
-    NonnullGCPtr<Object> Intrinsics::snake_namespace##snake_name##_prototype()                                                                                                                                     \
-    {                                                                                                                                                                                                              \
-        if (!m_##snake_namespace##snake_name##_prototype)                                                                                                                                                          \
-            initialize_##snake_namespace##snake_name();                                                                                                                                                            \
-        return *m_##snake_namespace##snake_name##_prototype;                                                                                                                                                       \
+#define __JS_ENUMERATE_INNER(ClassName, snake_name, PrototypeName, ConstructorName, Namespace, snake_namespace)                                          \
+    void Intrinsics::initialize_##snake_namespace##snake_name()                                                                                          \
+    {                                                                                                                                                    \
+        auto& vm = this->vm();                                                                                                                           \
+                                                                                                                                                         \
+        VERIFY(!m_##snake_namespace##snake_name##_prototype);                                                                                            \
+        VERIFY(!m_##snake_namespace##snake_name##_constructor);                                                                                          \
+        if constexpr (IsTypedArrayConstructor<Namespace::ConstructorName>) {                                                                             \
+            m_##snake_namespace##snake_name##_prototype = heap().allocate<Namespace::PrototypeName>(m_realm, *typed_array_prototype());                  \
+            m_##snake_namespace##snake_name##_constructor = heap().allocate<Namespace::ConstructorName>(m_realm, m_realm, *typed_array_constructor());   \
+        } else {                                                                                                                                         \
+            m_##snake_namespace##snake_name##_prototype = heap().allocate<Namespace::PrototypeName>(m_realm, m_realm);                                   \
+            m_##snake_namespace##snake_name##_constructor = heap().allocate<Namespace::ConstructorName>(m_realm, m_realm);                               \
+        }                                                                                                                                                \
+                                                                                                                                                         \
+        /* FIXME: Add these special cases to JS_ENUMERATE_NATIVE_OBJECTS */                                                                              \
+        if constexpr (IsSame<Namespace::ConstructorName, BigIntConstructor>)                                                                             \
+            initialize_constructor(vm, vm.names.BigInt, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);    \
+        else if constexpr (IsSame<Namespace::ConstructorName, BooleanConstructor>)                                                                       \
+            initialize_constructor(vm, vm.names.Boolean, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);   \
+        else if constexpr (IsSame<Namespace::ConstructorName, FunctionConstructor>)                                                                      \
+            initialize_constructor(vm, vm.names.Function, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);  \
+        else if constexpr (IsSame<Namespace::ConstructorName, NumberConstructor>)                                                                        \
+            initialize_constructor(vm, vm.names.Number, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);    \
+        else if constexpr (IsSame<Namespace::ConstructorName, RegExpConstructor>)                                                                        \
+            initialize_constructor(vm, vm.names.RegExp, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);    \
+        else if constexpr (IsSame<Namespace::ConstructorName, StringConstructor>)                                                                        \
+            initialize_constructor(vm, vm.names.String, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);    \
+        else if constexpr (IsSame<Namespace::ConstructorName, SymbolConstructor>)                                                                        \
+            initialize_constructor(vm, vm.names.Symbol, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype);    \
+        else                                                                                                                                             \
+            initialize_constructor(vm, vm.names.ClassName, *m_##snake_namespace##snake_name##_constructor, m_##snake_namespace##snake_name##_prototype); \
+    }                                                                                                                                                    \
+                                                                                                                                                         \
+    NonnullGCPtr<Namespace::ConstructorName> Intrinsics::snake_namespace##snake_name##_constructor()                                                     \
+    {                                                                                                                                                    \
+        if (!m_##snake_namespace##snake_name##_constructor)                                                                                              \
+            initialize_##snake_namespace##snake_name();                                                                                                  \
+        return *m_##snake_namespace##snake_name##_constructor;                                                                                           \
+    }                                                                                                                                                    \
+                                                                                                                                                         \
+    NonnullGCPtr<Object> Intrinsics::snake_namespace##snake_name##_prototype()                                                                           \
+    {                                                                                                                                                    \
+        if (!m_##snake_namespace##snake_name##_prototype)                                                                                                \
+            initialize_##snake_namespace##snake_name();                                                                                                  \
+        return *m_##snake_namespace##snake_name##_prototype;                                                                                             \
     }
 
 #define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName, ArrayType) \
@@ -339,12 +339,12 @@ JS_ENUMERATE_TEMPORAL_OBJECTS
 
 #undef __JS_ENUMERATE_INNER
 
-#define __JS_ENUMERATE(ClassName, snake_name)                                                                                                   \
-    NonnullGCPtr<ClassName> Intrinsics::snake_name##_object()                                                                                   \
-    {                                                                                                                                           \
-        if (!m_##snake_name##_object)                                                                                                           \
-            m_##snake_name##_object = heap().allocate<ClassName>(m_realm, m_realm).release_allocated_value_but_fixme_should_propagate_errors(); \
-        return *m_##snake_name##_object;                                                                                                        \
+#define __JS_ENUMERATE(ClassName, snake_name)                                       \
+    NonnullGCPtr<ClassName> Intrinsics::snake_name##_object()                       \
+    {                                                                               \
+        if (!m_##snake_name##_object)                                               \
+            m_##snake_name##_object = heap().allocate<ClassName>(m_realm, m_realm); \
+        return *m_##snake_name##_object;                                            \
     }
 JS_ENUMERATE_BUILTIN_NAMESPACE_OBJECTS
 #undef __JS_ENUMERATE
diff --git a/Userland/Libraries/LibJS/Runtime/Iterator.cpp b/Userland/Libraries/LibJS/Runtime/Iterator.cpp
index 2cb4447c25f..8a1f2ce746b 100644
--- a/Userland/Libraries/LibJS/Runtime/Iterator.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Iterator.cpp
@@ -15,9 +15,9 @@
 
 namespace JS {
 
-ThrowCompletionOr<NonnullGCPtr<Iterator>> Iterator::create(Realm& realm, Object& prototype, IteratorRecord iterated)
+NonnullGCPtr<Iterator> Iterator::create(Realm& realm, Object& prototype, IteratorRecord iterated)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Iterator>(realm, prototype, move(iterated)));
+    return realm.heap().allocate<Iterator>(realm, prototype, move(iterated));
 }
 
 Iterator::Iterator(Object& prototype, IteratorRecord iterated)
diff --git a/Userland/Libraries/LibJS/Runtime/Iterator.h b/Userland/Libraries/LibJS/Runtime/Iterator.h
index f826ca38760..fefa8fc57e3 100644
--- a/Userland/Libraries/LibJS/Runtime/Iterator.h
+++ b/Userland/Libraries/LibJS/Runtime/Iterator.h
@@ -27,7 +27,7 @@ class Iterator : public Object {
     JS_OBJECT(Iterator, Object);
 
 public:
-    static ThrowCompletionOr<NonnullGCPtr<Iterator>> create(Realm&, Object& prototype, IteratorRecord iterated);
+    static NonnullGCPtr<Iterator> create(Realm&, Object& prototype, IteratorRecord iterated);
 
     IteratorRecord const& iterated() const { return m_iterated; }
 
diff --git a/Userland/Libraries/LibJS/Runtime/IteratorConstructor.cpp b/Userland/Libraries/LibJS/Runtime/IteratorConstructor.cpp
index 8ad7ff1ad89..1b104e84a9e 100644
--- a/Userland/Libraries/LibJS/Runtime/IteratorConstructor.cpp
+++ b/Userland/Libraries/LibJS/Runtime/IteratorConstructor.cpp
@@ -78,7 +78,7 @@ JS_DEFINE_NATIVE_FUNCTION(IteratorConstructor::from)
 
     // 4. Let wrapper be OrdinaryObjectCreate(%WrapForValidIteratorPrototype%, « [[Iterated]] »).
     // 5. Set wrapper.[[Iterated]] to iteratorRecord.
-    auto wrapper = MUST_OR_THROW_OOM(Iterator::create(realm, realm.intrinsics().wrap_for_valid_iterator_prototype(), move(iterator_record)));
+    auto wrapper = Iterator::create(realm, realm.intrinsics().wrap_for_valid_iterator_prototype(), move(iterator_record));
 
     // 6. Return wrapper.
     return wrapper;
diff --git a/Userland/Libraries/LibJS/Runtime/IteratorHelper.cpp b/Userland/Libraries/LibJS/Runtime/IteratorHelper.cpp
index 011e1439b8b..345ec4ca159 100644
--- a/Userland/Libraries/LibJS/Runtime/IteratorHelper.cpp
+++ b/Userland/Libraries/LibJS/Runtime/IteratorHelper.cpp
@@ -13,7 +13,7 @@ namespace JS {
 
 ThrowCompletionOr<NonnullGCPtr<IteratorHelper>> IteratorHelper::create(Realm& realm, IteratorRecord underlying_iterator, Closure closure, Optional<AbruptClosure> abrupt_closure)
 {
-    return TRY(realm.heap().allocate<IteratorHelper>(realm, realm, realm.intrinsics().iterator_helper_prototype(), move(underlying_iterator), move(closure), move(abrupt_closure)));
+    return realm.heap().allocate<IteratorHelper>(realm, realm, realm.intrinsics().iterator_helper_prototype(), move(underlying_iterator), move(closure), move(abrupt_closure));
 }
 
 IteratorHelper::IteratorHelper(Realm& realm, Object& prototype, IteratorRecord underlying_iterator, Closure closure, Optional<AbruptClosure> abrupt_closure)
diff --git a/Userland/Libraries/LibJS/Runtime/IteratorPrototype.cpp b/Userland/Libraries/LibJS/Runtime/IteratorPrototype.cpp
index 77884894222..c7c84cf8d35 100644
--- a/Userland/Libraries/LibJS/Runtime/IteratorPrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/IteratorPrototype.cpp
@@ -439,7 +439,7 @@ JS_DEFINE_NATIVE_FUNCTION(IteratorPrototype::flat_map)
     // 4. Let iterated be ? GetIteratorDirect(O).
     auto iterated = TRY(get_iterator_direct(vm, object));
 
-    auto flat_map_iterator = MUST_OR_THROW_OOM(vm.heap().allocate<FlatMapIterator>(realm));
+    auto flat_map_iterator = vm.heap().allocate<FlatMapIterator>(realm);
 
     // 5. Let closure be a new Abstract Closure with no parameters that captures iterated and mapper and performs the following steps when called:
     IteratorHelper::Closure closure = [flat_map_iterator, mapper = NonnullGCPtr { mapper.as_function() }](auto& vm, auto& iterator) mutable -> ThrowCompletionOr<Value> {
diff --git a/Userland/Libraries/LibJS/Runtime/Map.cpp b/Userland/Libraries/LibJS/Runtime/Map.cpp
index 6bc86460abe..7ec3ec89661 100644
--- a/Userland/Libraries/LibJS/Runtime/Map.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Map.cpp
@@ -10,7 +10,7 @@ namespace JS {
 
 NonnullGCPtr<Map> Map::create(Realm& realm)
 {
-    return realm.heap().allocate<Map>(realm, realm.intrinsics().map_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<Map>(realm, realm.intrinsics().map_prototype());
 }
 
 Map::Map(Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/MapIterator.cpp b/Userland/Libraries/LibJS/Runtime/MapIterator.cpp
index 79442203c77..99c17b52a36 100644
--- a/Userland/Libraries/LibJS/Runtime/MapIterator.cpp
+++ b/Userland/Libraries/LibJS/Runtime/MapIterator.cpp
@@ -11,7 +11,7 @@ namespace JS {
 
 NonnullGCPtr<MapIterator> MapIterator::create(Realm& realm, Map& map, Object::PropertyKind iteration_kind)
 {
-    return realm.heap().allocate<MapIterator>(realm, map, iteration_kind, realm.intrinsics().map_iterator_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<MapIterator>(realm, map, iteration_kind, realm.intrinsics().map_iterator_prototype());
 }
 
 MapIterator::MapIterator(Map& map, Object::PropertyKind iteration_kind, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/NativeFunction.cpp b/Userland/Libraries/LibJS/Runtime/NativeFunction.cpp
index 2af038f072a..54cd62ff8be 100644
--- a/Userland/Libraries/LibJS/Runtime/NativeFunction.cpp
+++ b/Userland/Libraries/LibJS/Runtime/NativeFunction.cpp
@@ -36,7 +36,7 @@ NonnullGCPtr<NativeFunction> NativeFunction::create(Realm& allocating_realm, Saf
     // 7. Set func.[[Extensible]] to true.
     // 8. Set func.[[Realm]] to realm.
     // 9. Set func.[[InitialName]] to null.
-    auto function = allocating_realm.heap().allocate<NativeFunction>(allocating_realm, move(behaviour), prototype.value(), *realm.value()).release_allocated_value_but_fixme_should_propagate_errors();
+    auto function = allocating_realm.heap().allocate<NativeFunction>(allocating_realm, move(behaviour), prototype.value(), *realm.value());
 
     // 10. Perform SetFunctionLength(func, length).
     function->set_function_length(length);
@@ -53,7 +53,7 @@ NonnullGCPtr<NativeFunction> NativeFunction::create(Realm& allocating_realm, Saf
 
 NonnullGCPtr<NativeFunction> NativeFunction::create(Realm& realm, DeprecatedFlyString const& name, SafeFunction<ThrowCompletionOr<Value>(VM&)> function)
 {
-    return realm.heap().allocate<NativeFunction>(realm, name, move(function), realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<NativeFunction>(realm, name, move(function), realm.intrinsics().function_prototype());
 }
 
 NativeFunction::NativeFunction(SafeFunction<ThrowCompletionOr<Value>(VM&)> native_function, Object* prototype, Realm& realm)
diff --git a/Userland/Libraries/LibJS/Runtime/NumberObject.cpp b/Userland/Libraries/LibJS/Runtime/NumberObject.cpp
index 343f93f735a..632d0b99d7f 100644
--- a/Userland/Libraries/LibJS/Runtime/NumberObject.cpp
+++ b/Userland/Libraries/LibJS/Runtime/NumberObject.cpp
@@ -11,7 +11,7 @@ namespace JS {
 
 NonnullGCPtr<NumberObject> NumberObject::create(Realm& realm, double value)
 {
-    return realm.heap().allocate<NumberObject>(realm, value, realm.intrinsics().number_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<NumberObject>(realm, value, realm.intrinsics().number_prototype());
 }
 
 NumberObject::NumberObject(double value, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/Object.cpp b/Userland/Libraries/LibJS/Runtime/Object.cpp
index a34ae29d980..79f3e31e4a7 100644
--- a/Userland/Libraries/LibJS/Runtime/Object.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Object.cpp
@@ -29,10 +29,10 @@ static HashMap<GCPtr<Object const>, HashMap<DeprecatedFlyString, Object::Intrins
 NonnullGCPtr<Object> Object::create(Realm& realm, Object* prototype)
 {
     if (!prototype)
-        return realm.heap().allocate<Object>(realm, realm.intrinsics().empty_object_shape()).release_allocated_value_but_fixme_should_propagate_errors();
+        return realm.heap().allocate<Object>(realm, realm.intrinsics().empty_object_shape());
     if (prototype == realm.intrinsics().object_prototype())
-        return realm.heap().allocate<Object>(realm, realm.intrinsics().new_object_shape()).release_allocated_value_but_fixme_should_propagate_errors();
-    return realm.heap().allocate<Object>(realm, ConstructWithPrototypeTag::Tag, *prototype).release_allocated_value_but_fixme_should_propagate_errors();
+        return realm.heap().allocate<Object>(realm, realm.intrinsics().new_object_shape());
+    return realm.heap().allocate<Object>(realm, ConstructWithPrototypeTag::Tag, *prototype);
 }
 
 Object::Object(GlobalObjectTag, Realm& realm)
diff --git a/Userland/Libraries/LibJS/Runtime/Promise.cpp b/Userland/Libraries/LibJS/Runtime/Promise.cpp
index 1cdf32ccfd0..51eb1f078fd 100644
--- a/Userland/Libraries/LibJS/Runtime/Promise.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Promise.cpp
@@ -44,7 +44,7 @@ ThrowCompletionOr<Object*> promise_resolve(VM& vm, Object& constructor, Value va
 
 NonnullGCPtr<Promise> Promise::create(Realm& realm)
 {
-    return realm.heap().allocate<Promise>(realm, realm.intrinsics().promise_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<Promise>(realm, realm.intrinsics().promise_prototype());
 }
 
 // 27.2 Promise Objects, https://tc39.es/ecma262/#sec-promise-objects
diff --git a/Userland/Libraries/LibJS/Runtime/PromiseCapability.cpp b/Userland/Libraries/LibJS/Runtime/PromiseCapability.cpp
index 427442771a0..4fa80c7d7a5 100644
--- a/Userland/Libraries/LibJS/Runtime/PromiseCapability.cpp
+++ b/Userland/Libraries/LibJS/Runtime/PromiseCapability.cpp
@@ -59,7 +59,7 @@ ThrowCompletionOr<NonnullGCPtr<PromiseCapability>> new_promise_capability(VM& vm
     // 2. NOTE: C is assumed to be a constructor function that supports the parameter conventions of the Promise constructor (see 27.2.3.1).
 
     // 3. Let resolvingFunctions be the Record { [[Resolve]]: undefined, [[Reject]]: undefined }.
-    auto resolving_functions = TRY(vm.heap().allocate<ResolvingFunctions>(realm));
+    auto resolving_functions = vm.heap().allocate<ResolvingFunctions>(realm);
 
     // 4. Let executorClosure be a new Abstract Closure with parameters (resolve, reject) that captures resolvingFunctions and performs the following steps when called:
     auto executor_closure = [resolving_functions](auto& vm) -> ThrowCompletionOr<Value> {
diff --git a/Userland/Libraries/LibJS/Runtime/PromiseResolvingElementFunctions.cpp b/Userland/Libraries/LibJS/Runtime/PromiseResolvingElementFunctions.cpp
index 99499971e27..c62f8f955cc 100644
--- a/Userland/Libraries/LibJS/Runtime/PromiseResolvingElementFunctions.cpp
+++ b/Userland/Libraries/LibJS/Runtime/PromiseResolvingElementFunctions.cpp
@@ -55,7 +55,7 @@ void PromiseResolvingElementFunction::visit_edges(Cell::Visitor& visitor)
 
 NonnullGCPtr<PromiseAllResolveElementFunction> PromiseAllResolveElementFunction::create(Realm& realm, size_t index, PromiseValueList& values, NonnullGCPtr<PromiseCapability const> capability, RemainingElements& remaining_elements)
 {
-    return realm.heap().allocate<PromiseAllResolveElementFunction>(realm, index, values, capability, remaining_elements, realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<PromiseAllResolveElementFunction>(realm, index, values, capability, remaining_elements, realm.intrinsics().function_prototype());
 }
 
 PromiseAllResolveElementFunction::PromiseAllResolveElementFunction(size_t index, PromiseValueList& values, NonnullGCPtr<PromiseCapability const> capability, RemainingElements& remaining_elements, Object& prototype)
@@ -87,7 +87,7 @@ ThrowCompletionOr<Value> PromiseAllResolveElementFunction::resolve_element()
 
 NonnullGCPtr<PromiseAllSettledResolveElementFunction> PromiseAllSettledResolveElementFunction::create(Realm& realm, size_t index, PromiseValueList& values, NonnullGCPtr<PromiseCapability const> capability, RemainingElements& remaining_elements)
 {
-    return realm.heap().allocate<PromiseAllSettledResolveElementFunction>(realm, index, values, capability, remaining_elements, realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<PromiseAllSettledResolveElementFunction>(realm, index, values, capability, remaining_elements, realm.intrinsics().function_prototype());
 }
 
 PromiseAllSettledResolveElementFunction::PromiseAllSettledResolveElementFunction(size_t index, PromiseValueList& values, NonnullGCPtr<PromiseCapability const> capability, RemainingElements& remaining_elements, Object& prototype)
@@ -128,7 +128,7 @@ ThrowCompletionOr<Value> PromiseAllSettledResolveElementFunction::resolve_elemen
 
 NonnullGCPtr<PromiseAllSettledRejectElementFunction> PromiseAllSettledRejectElementFunction::create(Realm& realm, size_t index, PromiseValueList& values, NonnullGCPtr<PromiseCapability const> capability, RemainingElements& remaining_elements)
 {
-    return realm.heap().allocate<PromiseAllSettledRejectElementFunction>(realm, index, values, capability, remaining_elements, realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<PromiseAllSettledRejectElementFunction>(realm, index, values, capability, remaining_elements, realm.intrinsics().function_prototype());
 }
 
 PromiseAllSettledRejectElementFunction::PromiseAllSettledRejectElementFunction(size_t index, PromiseValueList& values, NonnullGCPtr<PromiseCapability const> capability, RemainingElements& remaining_elements, Object& prototype)
@@ -169,7 +169,7 @@ ThrowCompletionOr<Value> PromiseAllSettledRejectElementFunction::resolve_element
 
 NonnullGCPtr<PromiseAnyRejectElementFunction> PromiseAnyRejectElementFunction::create(Realm& realm, size_t index, PromiseValueList& errors, NonnullGCPtr<PromiseCapability const> capability, RemainingElements& remaining_elements)
 {
-    return realm.heap().allocate<PromiseAnyRejectElementFunction>(realm, index, errors, capability, remaining_elements, realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<PromiseAnyRejectElementFunction>(realm, index, errors, capability, remaining_elements, realm.intrinsics().function_prototype());
 }
 
 PromiseAnyRejectElementFunction::PromiseAnyRejectElementFunction(size_t index, PromiseValueList& errors, NonnullGCPtr<PromiseCapability const> capability, RemainingElements& remaining_elements, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/PromiseResolvingFunction.cpp b/Userland/Libraries/LibJS/Runtime/PromiseResolvingFunction.cpp
index d0b636731ba..d4d178d963a 100644
--- a/Userland/Libraries/LibJS/Runtime/PromiseResolvingFunction.cpp
+++ b/Userland/Libraries/LibJS/Runtime/PromiseResolvingFunction.cpp
@@ -13,7 +13,7 @@ namespace JS {
 
 NonnullGCPtr<PromiseResolvingFunction> PromiseResolvingFunction::create(Realm& realm, Promise& promise, AlreadyResolved& already_resolved, FunctionType function)
 {
-    return realm.heap().allocate<PromiseResolvingFunction>(realm, promise, already_resolved, move(function), realm.intrinsics().function_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<PromiseResolvingFunction>(realm, promise, already_resolved, move(function), realm.intrinsics().function_prototype());
 }
 
 PromiseResolvingFunction::PromiseResolvingFunction(Promise& promise, AlreadyResolved& already_resolved, FunctionType native_function, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/ProxyObject.cpp b/Userland/Libraries/LibJS/Runtime/ProxyObject.cpp
index e3f270fcd2a..c91b06c1bae 100644
--- a/Userland/Libraries/LibJS/Runtime/ProxyObject.cpp
+++ b/Userland/Libraries/LibJS/Runtime/ProxyObject.cpp
@@ -17,7 +17,7 @@ namespace JS {
 
 NonnullGCPtr<ProxyObject> ProxyObject::create(Realm& realm, Object& target, Object& handler)
 {
-    return realm.heap().allocate<ProxyObject>(realm, target, handler, realm.intrinsics().object_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<ProxyObject>(realm, target, handler, realm.intrinsics().object_prototype());
 }
 
 ProxyObject::ProxyObject(Object& target, Object& handler, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/RegExpObject.cpp b/Userland/Libraries/LibJS/Runtime/RegExpObject.cpp
index d05d7e62946..6d41cdf0580 100644
--- a/Userland/Libraries/LibJS/Runtime/RegExpObject.cpp
+++ b/Userland/Libraries/LibJS/Runtime/RegExpObject.cpp
@@ -132,12 +132,12 @@ ThrowCompletionOr<DeprecatedString> parse_regex_pattern(VM& vm, StringView patte
 
 NonnullGCPtr<RegExpObject> RegExpObject::create(Realm& realm)
 {
-    return realm.heap().allocate<RegExpObject>(realm, realm.intrinsics().regexp_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<RegExpObject>(realm, realm.intrinsics().regexp_prototype());
 }
 
 NonnullGCPtr<RegExpObject> RegExpObject::create(Realm& realm, Regex<ECMA262> regex, DeprecatedString pattern, DeprecatedString flags)
 {
-    return realm.heap().allocate<RegExpObject>(realm, move(regex), move(pattern), move(flags), realm.intrinsics().regexp_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<RegExpObject>(realm, move(regex), move(pattern), move(flags), realm.intrinsics().regexp_prototype());
 }
 
 RegExpObject::RegExpObject(Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/RegExpStringIterator.cpp b/Userland/Libraries/LibJS/Runtime/RegExpStringIterator.cpp
index c0074c5c11a..1c904859341 100644
--- a/Userland/Libraries/LibJS/Runtime/RegExpStringIterator.cpp
+++ b/Userland/Libraries/LibJS/Runtime/RegExpStringIterator.cpp
@@ -12,7 +12,7 @@ namespace JS {
 // 22.2.9.1 CreateRegExpStringIterator ( R, S, global, fullUnicode ), https://tc39.es/ecma262/#sec-createregexpstringiterator
 NonnullGCPtr<RegExpStringIterator> RegExpStringIterator::create(Realm& realm, Object& regexp_object, Utf16String string, bool global, bool unicode)
 {
-    return realm.heap().allocate<RegExpStringIterator>(realm, realm.intrinsics().regexp_string_iterator_prototype(), regexp_object, move(string), global, unicode).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<RegExpStringIterator>(realm, realm.intrinsics().regexp_string_iterator_prototype(), regexp_object, move(string), global, unicode);
 }
 
 RegExpStringIterator::RegExpStringIterator(Object& prototype, Object& regexp_object, Utf16String string, bool global, bool unicode)
diff --git a/Userland/Libraries/LibJS/Runtime/Set.cpp b/Userland/Libraries/LibJS/Runtime/Set.cpp
index ab39498fc9a..c603ba37497 100644
--- a/Userland/Libraries/LibJS/Runtime/Set.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Set.cpp
@@ -10,7 +10,7 @@ namespace JS {
 
 NonnullGCPtr<Set> Set::create(Realm& realm)
 {
-    return realm.heap().allocate<Set>(realm, realm.intrinsics().set_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<Set>(realm, realm.intrinsics().set_prototype());
 }
 
 Set::Set(Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/SetIterator.cpp b/Userland/Libraries/LibJS/Runtime/SetIterator.cpp
index 120c98a3328..cdef48b2d83 100644
--- a/Userland/Libraries/LibJS/Runtime/SetIterator.cpp
+++ b/Userland/Libraries/LibJS/Runtime/SetIterator.cpp
@@ -11,7 +11,7 @@ namespace JS {
 
 NonnullGCPtr<SetIterator> SetIterator::create(Realm& realm, Set& set, Object::PropertyKind iteration_kind)
 {
-    return realm.heap().allocate<SetIterator>(realm, set, iteration_kind, realm.intrinsics().set_iterator_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<SetIterator>(realm, set, iteration_kind, realm.intrinsics().set_iterator_prototype());
 }
 
 SetIterator::SetIterator(Set& set, Object::PropertyKind iteration_kind, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/StringConstructor.cpp b/Userland/Libraries/LibJS/Runtime/StringConstructor.cpp
index 65c9e96baea..f616e2d320f 100644
--- a/Userland/Libraries/LibJS/Runtime/StringConstructor.cpp
+++ b/Userland/Libraries/LibJS/Runtime/StringConstructor.cpp
@@ -79,7 +79,7 @@ ThrowCompletionOr<NonnullGCPtr<Object>> StringConstructor::construct(FunctionObj
 
     // 4. Return StringCreate(s, ? GetPrototypeFromConstructor(NewTarget, "%String.prototype%")).
     auto* prototype = TRY(get_prototype_from_constructor(vm, new_target, &Intrinsics::string_prototype));
-    return MUST_OR_THROW_OOM(StringObject::create(realm, *primitive_string, *prototype));
+    return StringObject::create(realm, *primitive_string, *prototype);
 }
 
 // 22.1.2.1 String.fromCharCode ( ...codeUnits ), https://tc39.es/ecma262/#sec-string.fromcharcode
diff --git a/Userland/Libraries/LibJS/Runtime/StringIterator.cpp b/Userland/Libraries/LibJS/Runtime/StringIterator.cpp
index e559728648b..e7b790cea27 100644
--- a/Userland/Libraries/LibJS/Runtime/StringIterator.cpp
+++ b/Userland/Libraries/LibJS/Runtime/StringIterator.cpp
@@ -12,7 +12,7 @@ namespace JS {
 
 NonnullGCPtr<StringIterator> StringIterator::create(Realm& realm, String string)
 {
-    return realm.heap().allocate<StringIterator>(realm, move(string), realm.intrinsics().string_iterator_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<StringIterator>(realm, move(string), realm.intrinsics().string_iterator_prototype());
 }
 
 StringIterator::StringIterator(String string, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/StringObject.cpp b/Userland/Libraries/LibJS/Runtime/StringObject.cpp
index 75fb3aeb093..ea04c0f9940 100644
--- a/Userland/Libraries/LibJS/Runtime/StringObject.cpp
+++ b/Userland/Libraries/LibJS/Runtime/StringObject.cpp
@@ -15,7 +15,7 @@
 namespace JS {
 
 // 10.4.3.4 StringCreate ( value, prototype ), https://tc39.es/ecma262/#sec-stringcreate
-ThrowCompletionOr<NonnullGCPtr<StringObject>> StringObject::create(Realm& realm, PrimitiveString& primitive_string, Object& prototype)
+NonnullGCPtr<StringObject> StringObject::create(Realm& realm, PrimitiveString& primitive_string, Object& prototype)
 {
     // 1. Let S be MakeBasicObject(« [[Prototype]], [[Extensible]], [[StringData]] »).
     // 2. Set S.[[Prototype]] to prototype.
@@ -26,7 +26,7 @@ ThrowCompletionOr<NonnullGCPtr<StringObject>> StringObject::create(Realm& realm,
     // 7. Let length be the length of value.
     // 8. Perform ! DefinePropertyOrThrow(S, "length", PropertyDescriptor { [[Value]]: 𝔽(length), [[Writable]]: false, [[Enumerable]]: false, [[Configurable]]: false }).
     // 9. Return S.
-    return MUST_OR_THROW_OOM(realm.heap().allocate<StringObject>(realm, primitive_string, prototype));
+    return realm.heap().allocate<StringObject>(realm, primitive_string, prototype);
 }
 
 StringObject::StringObject(PrimitiveString& string, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/StringObject.h b/Userland/Libraries/LibJS/Runtime/StringObject.h
index 57746819335..9be24bcea0c 100644
--- a/Userland/Libraries/LibJS/Runtime/StringObject.h
+++ b/Userland/Libraries/LibJS/Runtime/StringObject.h
@@ -14,7 +14,7 @@ class StringObject : public Object {
     JS_OBJECT(StringObject, Object);
 
 public:
-    static ThrowCompletionOr<NonnullGCPtr<StringObject>> create(Realm&, PrimitiveString&, Object& prototype);
+    [[nodiscard]] static NonnullGCPtr<StringObject> create(Realm&, PrimitiveString&, Object& prototype);
 
     virtual void initialize(Realm&) override;
     virtual ~StringObject() override = default;
diff --git a/Userland/Libraries/LibJS/Runtime/SuppressedError.cpp b/Userland/Libraries/LibJS/Runtime/SuppressedError.cpp
index b98ce1a46ff..92f463bce66 100644
--- a/Userland/Libraries/LibJS/Runtime/SuppressedError.cpp
+++ b/Userland/Libraries/LibJS/Runtime/SuppressedError.cpp
@@ -12,7 +12,7 @@ namespace JS {
 
 NonnullGCPtr<SuppressedError> SuppressedError::create(Realm& realm)
 {
-    return realm.heap().allocate<SuppressedError>(realm, realm.intrinsics().suppressed_error_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<SuppressedError>(realm, realm.intrinsics().suppressed_error_prototype());
 }
 
 SuppressedError::SuppressedError(Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/SymbolObject.cpp b/Userland/Libraries/LibJS/Runtime/SymbolObject.cpp
index 37b4f506b2b..a727bb43b90 100644
--- a/Userland/Libraries/LibJS/Runtime/SymbolObject.cpp
+++ b/Userland/Libraries/LibJS/Runtime/SymbolObject.cpp
@@ -12,7 +12,7 @@ namespace JS {
 
 NonnullGCPtr<SymbolObject> SymbolObject::create(Realm& realm, Symbol& primitive_symbol)
 {
-    return realm.heap().allocate<SymbolObject>(realm, primitive_symbol, realm.intrinsics().symbol_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<SymbolObject>(realm, primitive_symbol, realm.intrinsics().symbol_prototype());
 }
 
 SymbolObject::SymbolObject(Symbol& symbol, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/Temporal.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/Temporal.cpp
index 54a79d362a0..dd69f8a5df5 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/Temporal.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/Temporal.cpp
@@ -36,7 +36,7 @@ void Temporal::initialize(Realm& realm)
     define_direct_property(vm.well_known_symbol_to_string_tag(), PrimitiveString::create(vm, "Temporal"_string), Attribute::Configurable);
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
-    define_direct_property(vm.names.Now, MUST(heap().allocate<Now>(realm, realm)), attr);
+    define_direct_property(vm.names.Now, heap().allocate<Now>(realm, realm), attr);
     define_intrinsic_accessor(vm.names.Calendar, attr, [](auto& realm) -> Value { return realm.intrinsics().temporal_calendar_constructor(); });
     define_intrinsic_accessor(vm.names.Duration, attr, [](auto& realm) -> Value { return realm.intrinsics().temporal_duration_constructor(); });
     define_intrinsic_accessor(vm.names.Instant, attr, [](auto& realm) -> Value { return realm.intrinsics().temporal_instant_constructor(); });
diff --git a/Userland/Libraries/LibJS/Runtime/TypedArray.cpp b/Userland/Libraries/LibJS/Runtime/TypedArray.cpp
index c21d9022dd5..202f72061d7 100644
--- a/Userland/Libraries/LibJS/Runtime/TypedArray.cpp
+++ b/Userland/Libraries/LibJS/Runtime/TypedArray.cpp
@@ -419,137 +419,137 @@ void TypedArrayBase::visit_edges(Visitor& visitor)
     visitor.visit(m_viewed_array_buffer);
 }
 
-#define JS_DEFINE_TYPED_ARRAY(ClassName, snake_name, PrototypeName, ConstructorName, Type)                                                                                             \
-    ThrowCompletionOr<NonnullGCPtr<ClassName>> ClassName::create(Realm& realm, u32 length, FunctionObject& new_target)                                                                 \
-    {                                                                                                                                                                                  \
-        auto* prototype = TRY(get_prototype_from_constructor(realm.vm(), new_target, &Intrinsics::snake_name##_prototype));                                                            \
-        auto array_buffer = TRY(ArrayBuffer::create(realm, length * sizeof(UnderlyingBufferDataType)));                                                                                \
-        return MUST_OR_THROW_OOM(realm.heap().allocate<ClassName>(realm, *prototype, length, *array_buffer));                                                                          \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    ThrowCompletionOr<NonnullGCPtr<ClassName>> ClassName::create(Realm& realm, u32 length)                                                                                             \
-    {                                                                                                                                                                                  \
-        auto array_buffer = TRY(ArrayBuffer::create(realm, length * sizeof(UnderlyingBufferDataType)));                                                                                \
-        return create(realm, length, *array_buffer);                                                                                                                                   \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    NonnullGCPtr<ClassName> ClassName::create(Realm& realm, u32 length, ArrayBuffer& array_buffer)                                                                                     \
-    {                                                                                                                                                                                  \
-        return realm.heap().allocate<ClassName>(realm, realm.intrinsics().snake_name##_prototype(), length, array_buffer).release_allocated_value_but_fixme_should_propagate_errors(); \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    ClassName::ClassName(Object& prototype, u32 length, ArrayBuffer& array_buffer)                                                                                                     \
-        : TypedArray(prototype,                                                                                                                                                        \
-            bit_cast<TypedArrayBase::IntrinsicConstructor>(&Intrinsics::snake_name##_constructor), length, array_buffer)                                                               \
-    {                                                                                                                                                                                  \
-        if constexpr (#ClassName##sv.is_one_of("BigInt64Array", "BigUint64Array"))                                                                                                     \
-            m_content_type = ContentType::BigInt;                                                                                                                                      \
-        else                                                                                                                                                                           \
-            m_content_type = ContentType::Number;                                                                                                                                      \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    ClassName::~ClassName()                                                                                                                                                            \
-    {                                                                                                                                                                                  \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    DeprecatedFlyString const& ClassName::element_name() const                                                                                                                         \
-    {                                                                                                                                                                                  \
-        return vm().names.ClassName.as_string();                                                                                                                                       \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    PrototypeName::PrototypeName(Object& prototype)                                                                                                                                    \
-        : Object(ConstructWithPrototypeTag::Tag, prototype)                                                                                                                            \
-    {                                                                                                                                                                                  \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    PrototypeName::~PrototypeName()                                                                                                                                                    \
-    {                                                                                                                                                                                  \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    void PrototypeName::initialize(Realm& realm)                                                                                                                                       \
-    {                                                                                                                                                                                  \
-        auto& vm = this->vm();                                                                                                                                                         \
-        Base::initialize(realm);                                                                                                                                                       \
-        define_direct_property(vm.names.BYTES_PER_ELEMENT, Value((i32)sizeof(Type)), 0);                                                                                               \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    ConstructorName::ConstructorName(Realm& realm, Object& prototype)                                                                                                                  \
-        : TypedArrayConstructor(realm.vm().names.ClassName.as_string(), prototype)                                                                                                     \
-    {                                                                                                                                                                                  \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    ConstructorName::~ConstructorName()                                                                                                                                                \
-    {                                                                                                                                                                                  \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    void ConstructorName::initialize(Realm& realm)                                                                                                                                     \
-    {                                                                                                                                                                                  \
-        auto& vm = this->vm();                                                                                                                                                         \
-        Base::initialize(realm);                                                                                                                                                       \
-                                                                                                                                                                                       \
-        /* 23.2.6.2 TypedArray.prototype, https://tc39.es/ecma262/#sec-typedarray.prototype */                                                                                         \
-        define_direct_property(vm.names.prototype, realm.intrinsics().snake_name##_prototype(), 0);                                                                                    \
-                                                                                                                                                                                       \
-        /* 23.2.6.1 TypedArray.BYTES_PER_ELEMENT, https://tc39.es/ecma262/#sec-typedarray.bytes_per_element */                                                                         \
-        define_direct_property(vm.names.BYTES_PER_ELEMENT, Value((i32)sizeof(Type)), 0);                                                                                               \
-                                                                                                                                                                                       \
-        define_direct_property(vm.names.length, Value(3), Attribute::Configurable);                                                                                                    \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    /* 23.2.5.1 TypedArray ( ...args ), https://tc39.es/ecma262/#sec-typedarray */                                                                                                     \
-    ThrowCompletionOr<Value> ConstructorName::call()                                                                                                                                   \
-    {                                                                                                                                                                                  \
-        auto& vm = this->vm();                                                                                                                                                         \
-        return vm.throw_completion<TypeError>(ErrorType::ConstructorWithoutNew, vm.names.ClassName);                                                                                   \
-    }                                                                                                                                                                                  \
-                                                                                                                                                                                       \
-    /* 23.2.5.1 TypedArray ( ...args ), https://tc39.es/ecma262/#sec-typedarray */                                                                                                     \
-    ThrowCompletionOr<NonnullGCPtr<Object>> ConstructorName::construct(FunctionObject& new_target)                                                                                     \
-    {                                                                                                                                                                                  \
-        auto& vm = this->vm();                                                                                                                                                         \
-        auto& realm = *vm.current_realm();                                                                                                                                             \
-                                                                                                                                                                                       \
-        if (vm.argument_count() == 0)                                                                                                                                                  \
-            return TRY(ClassName::create(realm, 0, new_target));                                                                                                                       \
-                                                                                                                                                                                       \
-        auto first_argument = vm.argument(0);                                                                                                                                          \
-        if (first_argument.is_object()) {                                                                                                                                              \
-            auto typed_array = TRY(ClassName::create(realm, 0, new_target));                                                                                                           \
-            if (first_argument.as_object().is_typed_array()) {                                                                                                                         \
-                auto& arg_typed_array = static_cast<TypedArrayBase&>(first_argument.as_object());                                                                                      \
-                TRY(initialize_typed_array_from_typed_array(vm, *typed_array, arg_typed_array));                                                                                       \
-            } else if (is<ArrayBuffer>(first_argument.as_object())) {                                                                                                                  \
-                auto& array_buffer = static_cast<ArrayBuffer&>(first_argument.as_object());                                                                                            \
-                TRY(initialize_typed_array_from_array_buffer(vm, *typed_array, array_buffer,                                                                                           \
-                    vm.argument(1), vm.argument(2)));                                                                                                                                  \
-            } else {                                                                                                                                                                   \
-                auto iterator = TRY(first_argument.get_method(vm, vm.well_known_symbol_iterator()));                                                                                   \
-                if (iterator) {                                                                                                                                                        \
-                    auto values = TRY(iterator_to_list(vm, TRY(get_iterator_from_method(vm, first_argument, *iterator))));                                                             \
-                    TRY(initialize_typed_array_from_list(vm, *typed_array, values));                                                                                                   \
-                } else {                                                                                                                                                               \
-                    TRY(initialize_typed_array_from_array_like(vm, *typed_array, first_argument.as_object()));                                                                         \
-                }                                                                                                                                                                      \
-            }                                                                                                                                                                          \
-            return typed_array;                                                                                                                                                        \
-        }                                                                                                                                                                              \
-                                                                                                                                                                                       \
-        auto array_length_or_error = first_argument.to_index(vm);                                                                                                                      \
-        if (array_length_or_error.is_error()) {                                                                                                                                        \
-            auto error = array_length_or_error.release_error();                                                                                                                        \
-            if (error.value()->is_object() && is<RangeError>(error.value()->as_object())) {                                                                                            \
-                /* Re-throw more specific RangeError */                                                                                                                                \
-                return vm.throw_completion<RangeError>(ErrorType::InvalidLength, "typed array");                                                                                       \
-            }                                                                                                                                                                          \
-            return error;                                                                                                                                                              \
-        }                                                                                                                                                                              \
-        auto array_length = array_length_or_error.release_value();                                                                                                                     \
-        if (array_length > NumericLimits<i32>::max() / sizeof(Type))                                                                                                                   \
-            return vm.throw_completion<RangeError>(ErrorType::InvalidLength, "typed array");                                                                                           \
-        /* FIXME: What is the best/correct behavior here? */                                                                                                                           \
-        if (Checked<u32>::multiplication_would_overflow(array_length, sizeof(Type)))                                                                                                   \
-            return vm.throw_completion<RangeError>(ErrorType::InvalidLength, "typed array");                                                                                           \
-        return TRY(ClassName::create(realm, array_length, new_target));                                                                                                                \
+#define JS_DEFINE_TYPED_ARRAY(ClassName, snake_name, PrototypeName, ConstructorName, Type)                                  \
+    ThrowCompletionOr<NonnullGCPtr<ClassName>> ClassName::create(Realm& realm, u32 length, FunctionObject& new_target)      \
+    {                                                                                                                       \
+        auto* prototype = TRY(get_prototype_from_constructor(realm.vm(), new_target, &Intrinsics::snake_name##_prototype)); \
+        auto array_buffer = TRY(ArrayBuffer::create(realm, length * sizeof(UnderlyingBufferDataType)));                     \
+        return realm.heap().allocate<ClassName>(realm, *prototype, length, *array_buffer);                                  \
+    }                                                                                                                       \
+                                                                                                                            \
+    ThrowCompletionOr<NonnullGCPtr<ClassName>> ClassName::create(Realm& realm, u32 length)                                  \
+    {                                                                                                                       \
+        auto array_buffer = TRY(ArrayBuffer::create(realm, length * sizeof(UnderlyingBufferDataType)));                     \
+        return create(realm, length, *array_buffer);                                                                        \
+    }                                                                                                                       \
+                                                                                                                            \
+    NonnullGCPtr<ClassName> ClassName::create(Realm& realm, u32 length, ArrayBuffer& array_buffer)                          \
+    {                                                                                                                       \
+        return realm.heap().allocate<ClassName>(realm, realm.intrinsics().snake_name##_prototype(), length, array_buffer);  \
+    }                                                                                                                       \
+                                                                                                                            \
+    ClassName::ClassName(Object& prototype, u32 length, ArrayBuffer& array_buffer)                                          \
+        : TypedArray(prototype,                                                                                             \
+            bit_cast<TypedArrayBase::IntrinsicConstructor>(&Intrinsics::snake_name##_constructor), length, array_buffer)    \
+    {                                                                                                                       \
+        if constexpr (#ClassName##sv.is_one_of("BigInt64Array", "BigUint64Array"))                                          \
+            m_content_type = ContentType::BigInt;                                                                           \
+        else                                                                                                                \
+            m_content_type = ContentType::Number;                                                                           \
+    }                                                                                                                       \
+                                                                                                                            \
+    ClassName::~ClassName()                                                                                                 \
+    {                                                                                                                       \
+    }                                                                                                                       \
+                                                                                                                            \
+    DeprecatedFlyString const& ClassName::element_name() const                                                              \
+    {                                                                                                                       \
+        return vm().names.ClassName.as_string();                                                                            \
+    }                                                                                                                       \
+                                                                                                                            \
+    PrototypeName::PrototypeName(Object& prototype)                                                                         \
+        : Object(ConstructWithPrototypeTag::Tag, prototype)                                                                 \
+    {                                                                                                                       \
+    }                                                                                                                       \
+                                                                                                                            \
+    PrototypeName::~PrototypeName()                                                                                         \
+    {                                                                                                                       \
+    }                                                                                                                       \
+                                                                                                                            \
+    void PrototypeName::initialize(Realm& realm)                                                                            \
+    {                                                                                                                       \
+        auto& vm = this->vm();                                                                                              \
+        Base::initialize(realm);                                                                                            \
+        define_direct_property(vm.names.BYTES_PER_ELEMENT, Value((i32)sizeof(Type)), 0);                                    \
+    }                                                                                                                       \
+                                                                                                                            \
+    ConstructorName::ConstructorName(Realm& realm, Object& prototype)                                                       \
+        : TypedArrayConstructor(realm.vm().names.ClassName.as_string(), prototype)                                          \
+    {                                                                                                                       \
+    }                                                                                                                       \
+                                                                                                                            \
+    ConstructorName::~ConstructorName()                                                                                     \
+    {                                                                                                                       \
+    }                                                                                                                       \
+                                                                                                                            \
+    void ConstructorName::initialize(Realm& realm)                                                                          \
+    {                                                                                                                       \
+        auto& vm = this->vm();                                                                                              \
+        Base::initialize(realm);                                                                                            \
+                                                                                                                            \
+        /* 23.2.6.2 TypedArray.prototype, https://tc39.es/ecma262/#sec-typedarray.prototype */                              \
+        define_direct_property(vm.names.prototype, realm.intrinsics().snake_name##_prototype(), 0);                         \
+                                                                                                                            \
+        /* 23.2.6.1 TypedArray.BYTES_PER_ELEMENT, https://tc39.es/ecma262/#sec-typedarray.bytes_per_element */              \
+        define_direct_property(vm.names.BYTES_PER_ELEMENT, Value((i32)sizeof(Type)), 0);                                    \
+                                                                                                                            \
+        define_direct_property(vm.names.length, Value(3), Attribute::Configurable);                                         \
+    }                                                                                                                       \
+                                                                                                                            \
+    /* 23.2.5.1 TypedArray ( ...args ), https://tc39.es/ecma262/#sec-typedarray */                                          \
+    ThrowCompletionOr<Value> ConstructorName::call()                                                                        \
+    {                                                                                                                       \
+        auto& vm = this->vm();                                                                                              \
+        return vm.throw_completion<TypeError>(ErrorType::ConstructorWithoutNew, vm.names.ClassName);                        \
+    }                                                                                                                       \
+                                                                                                                            \
+    /* 23.2.5.1 TypedArray ( ...args ), https://tc39.es/ecma262/#sec-typedarray */                                          \
+    ThrowCompletionOr<NonnullGCPtr<Object>> ConstructorName::construct(FunctionObject& new_target)                          \
+    {                                                                                                                       \
+        auto& vm = this->vm();                                                                                              \
+        auto& realm = *vm.current_realm();                                                                                  \
+                                                                                                                            \
+        if (vm.argument_count() == 0)                                                                                       \
+            return TRY(ClassName::create(realm, 0, new_target));                                                            \
+                                                                                                                            \
+        auto first_argument = vm.argument(0);                                                                               \
+        if (first_argument.is_object()) {                                                                                   \
+            auto typed_array = TRY(ClassName::create(realm, 0, new_target));                                                \
+            if (first_argument.as_object().is_typed_array()) {                                                              \
+                auto& arg_typed_array = static_cast<TypedArrayBase&>(first_argument.as_object());                           \
+                TRY(initialize_typed_array_from_typed_array(vm, *typed_array, arg_typed_array));                            \
+            } else if (is<ArrayBuffer>(first_argument.as_object())) {                                                       \
+                auto& array_buffer = static_cast<ArrayBuffer&>(first_argument.as_object());                                 \
+                TRY(initialize_typed_array_from_array_buffer(vm, *typed_array, array_buffer,                                \
+                    vm.argument(1), vm.argument(2)));                                                                       \
+            } else {                                                                                                        \
+                auto iterator = TRY(first_argument.get_method(vm, vm.well_known_symbol_iterator()));                        \
+                if (iterator) {                                                                                             \
+                    auto values = TRY(iterator_to_list(vm, TRY(get_iterator_from_method(vm, first_argument, *iterator))));  \
+                    TRY(initialize_typed_array_from_list(vm, *typed_array, values));                                        \
+                } else {                                                                                                    \
+                    TRY(initialize_typed_array_from_array_like(vm, *typed_array, first_argument.as_object()));              \
+                }                                                                                                           \
+            }                                                                                                               \
+            return typed_array;                                                                                             \
+        }                                                                                                                   \
+                                                                                                                            \
+        auto array_length_or_error = first_argument.to_index(vm);                                                           \
+        if (array_length_or_error.is_error()) {                                                                             \
+            auto error = array_length_or_error.release_error();                                                             \
+            if (error.value()->is_object() && is<RangeError>(error.value()->as_object())) {                                 \
+                /* Re-throw more specific RangeError */                                                                     \
+                return vm.throw_completion<RangeError>(ErrorType::InvalidLength, "typed array");                            \
+            }                                                                                                               \
+            return error;                                                                                                   \
+        }                                                                                                                   \
+        auto array_length = array_length_or_error.release_value();                                                          \
+        if (array_length > NumericLimits<i32>::max() / sizeof(Type))                                                        \
+            return vm.throw_completion<RangeError>(ErrorType::InvalidLength, "typed array");                                \
+        /* FIXME: What is the best/correct behavior here? */                                                                \
+        if (Checked<u32>::multiplication_would_overflow(array_length, sizeof(Type)))                                        \
+            return vm.throw_completion<RangeError>(ErrorType::InvalidLength, "typed array");                                \
+        return TRY(ClassName::create(realm, array_length, new_target));                                                     \
     }
 
 #undef __JS_ENUMERATE
diff --git a/Userland/Libraries/LibJS/Runtime/Value.cpp b/Userland/Libraries/LibJS/Runtime/Value.cpp
index b6cab1da150..42147d823d2 100644
--- a/Userland/Libraries/LibJS/Runtime/Value.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Value.cpp
@@ -566,7 +566,7 @@ ThrowCompletionOr<NonnullGCPtr<Object>> Value::to_object(VM& vm) const
     // String
     case STRING_TAG:
         // Return a new String object whose [[StringData]] internal slot is set to argument. See 22.1 for a description of String objects.
-        return MUST_OR_THROW_OOM(StringObject::create(realm, const_cast<JS::PrimitiveString&>(as_string()), realm.intrinsics().string_prototype()));
+        return StringObject::create(realm, const_cast<JS::PrimitiveString&>(as_string()), realm.intrinsics().string_prototype());
     // Symbol
     case SYMBOL_TAG:
         // Return a new Symbol object whose [[SymbolData]] internal slot is set to argument. See 20.4 for a description of Symbol objects.
diff --git a/Userland/Libraries/LibJS/Runtime/WeakMap.cpp b/Userland/Libraries/LibJS/Runtime/WeakMap.cpp
index e17d342858c..e8ea40a0a96 100644
--- a/Userland/Libraries/LibJS/Runtime/WeakMap.cpp
+++ b/Userland/Libraries/LibJS/Runtime/WeakMap.cpp
@@ -10,7 +10,7 @@ namespace JS {
 
 NonnullGCPtr<WeakMap> WeakMap::create(Realm& realm)
 {
-    return realm.heap().allocate<WeakMap>(realm, realm.intrinsics().weak_map_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<WeakMap>(realm, realm.intrinsics().weak_map_prototype());
 }
 
 WeakMap::WeakMap(Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/WeakRef.cpp b/Userland/Libraries/LibJS/Runtime/WeakRef.cpp
index 10c87623212..05a745878d2 100644
--- a/Userland/Libraries/LibJS/Runtime/WeakRef.cpp
+++ b/Userland/Libraries/LibJS/Runtime/WeakRef.cpp
@@ -10,12 +10,12 @@ namespace JS {
 
 NonnullGCPtr<WeakRef> WeakRef::create(Realm& realm, Object& value)
 {
-    return realm.heap().allocate<WeakRef>(realm, value, realm.intrinsics().weak_ref_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<WeakRef>(realm, value, realm.intrinsics().weak_ref_prototype());
 }
 
 NonnullGCPtr<WeakRef> WeakRef::create(Realm& realm, Symbol& value)
 {
-    return realm.heap().allocate<WeakRef>(realm, value, realm.intrinsics().weak_ref_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<WeakRef>(realm, value, realm.intrinsics().weak_ref_prototype());
 }
 
 WeakRef::WeakRef(Object& value, Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/WeakSet.cpp b/Userland/Libraries/LibJS/Runtime/WeakSet.cpp
index 5efa3bf0203..be911056bde 100644
--- a/Userland/Libraries/LibJS/Runtime/WeakSet.cpp
+++ b/Userland/Libraries/LibJS/Runtime/WeakSet.cpp
@@ -10,7 +10,7 @@ namespace JS {
 
 NonnullGCPtr<WeakSet> WeakSet::create(Realm& realm)
 {
-    return realm.heap().allocate<WeakSet>(realm, realm.intrinsics().weak_set_prototype()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<WeakSet>(realm, realm.intrinsics().weak_set_prototype());
 }
 
 WeakSet::WeakSet(Object& prototype)
diff --git a/Userland/Libraries/LibJS/Runtime/WrappedFunction.cpp b/Userland/Libraries/LibJS/Runtime/WrappedFunction.cpp
index 18693844101..42345686634 100644
--- a/Userland/Libraries/LibJS/Runtime/WrappedFunction.cpp
+++ b/Userland/Libraries/LibJS/Runtime/WrappedFunction.cpp
@@ -22,7 +22,7 @@ ThrowCompletionOr<NonnullGCPtr<WrappedFunction>> WrappedFunction::create(Realm&
     // 5. Set wrapped.[[WrappedTargetFunction]] to Target.
     // 6. Set wrapped.[[Realm]] to callerRealm.
     auto& prototype = *caller_realm.intrinsics().function_prototype();
-    auto wrapped = MUST_OR_THROW_OOM(vm.heap().allocate<WrappedFunction>(realm, caller_realm, target, prototype));
+    auto wrapped = vm.heap().allocate<WrappedFunction>(realm, caller_realm, target, prototype);
 
     // 7. Let result be CopyNameAndLength(wrapped, Target).
     auto result = copy_name_and_length(vm, *wrapped, target);
diff --git a/Userland/Libraries/LibTest/JavaScriptTestRunner.h b/Userland/Libraries/LibTest/JavaScriptTestRunner.h
index 3585cd0de98..8d204ca8ec8 100644
--- a/Userland/Libraries/LibTest/JavaScriptTestRunner.h
+++ b/Userland/Libraries/LibTest/JavaScriptTestRunner.h
@@ -292,7 +292,7 @@ inline JSFileResult TestRunner::run_file_test(DeprecatedString const& test_path)
         *g_vm,
         [&](JS::Realm& realm_) -> JS::GlobalObject* {
             realm = &realm_;
-            global_object = g_vm->heap().allocate<TestRunnerGlobalObject>(*realm, *realm).release_allocated_value_but_fixme_should_propagate_errors();
+            global_object = g_vm->heap().allocate<TestRunnerGlobalObject>(*realm, *realm);
             return global_object;
         },
         nullptr));
diff --git a/Userland/Libraries/LibWeb/Bindings/MainThreadVM.cpp b/Userland/Libraries/LibWeb/Bindings/MainThreadVM.cpp
index bb7895612c4..dd42da33e8b 100644
--- a/Userland/Libraries/LibWeb/Bindings/MainThreadVM.cpp
+++ b/Userland/Libraries/LibWeb/Bindings/MainThreadVM.cpp
@@ -174,7 +174,7 @@ ErrorOr<void> initialize_main_thread_vm()
                     /* .promise = */ promise,
                     /* .reason = */ promise.result(),
                 };
-                auto promise_rejection_event = HTML::PromiseRejectionEvent::create(HTML::relevant_realm(global), HTML::EventNames::rejectionhandled, event_init).release_value_but_fixme_should_propagate_errors();
+                auto promise_rejection_event = HTML::PromiseRejectionEvent::create(HTML::relevant_realm(global), HTML::EventNames::rejectionhandled, event_init);
                 window.dispatch_event(promise_rejection_event);
             });
             break;
diff --git a/Userland/Libraries/LibWeb/Bindings/OptionConstructor.cpp b/Userland/Libraries/LibWeb/Bindings/OptionConstructor.cpp
index 9fd74eaa80d..89a116604af 100644
--- a/Userland/Libraries/LibWeb/Bindings/OptionConstructor.cpp
+++ b/Userland/Libraries/LibWeb/Bindings/OptionConstructor.cpp
@@ -53,7 +53,7 @@ JS::ThrowCompletionOr<JS::NonnullGCPtr<JS::Object>> OptionConstructor::construct
     if (vm.argument_count() > 0) {
         auto text = TRY(vm.argument(0).to_deprecated_string(vm));
         if (!text.is_empty()) {
-            auto new_text_node = MUST_OR_THROW_OOM(vm.heap().allocate<DOM::Text>(realm, document, text));
+            auto new_text_node = vm.heap().allocate<DOM::Text>(realm, document, text);
             MUST(option_element->append_child(*new_text_node));
         }
     }
diff --git a/Userland/Libraries/LibWeb/CSS/CSSFontFaceRule.cpp b/Userland/Libraries/LibWeb/CSS/CSSFontFaceRule.cpp
index 35141696095..30114d6c9d7 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSFontFaceRule.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSFontFaceRule.cpp
@@ -14,9 +14,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSFontFaceRule>> CSSFontFaceRule::create(JS::Realm& realm, FontFace&& font_face)
+JS::NonnullGCPtr<CSSFontFaceRule> CSSFontFaceRule::create(JS::Realm& realm, FontFace&& font_face)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CSSFontFaceRule>(realm, realm, move(font_face)));
+    return realm.heap().allocate<CSSFontFaceRule>(realm, realm, move(font_face));
 }
 
 CSSFontFaceRule::CSSFontFaceRule(JS::Realm& realm, FontFace&& font_face)
diff --git a/Userland/Libraries/LibWeb/CSS/CSSFontFaceRule.h b/Userland/Libraries/LibWeb/CSS/CSSFontFaceRule.h
index b467045efdb..6986b3ae991 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSFontFaceRule.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSFontFaceRule.h
@@ -16,7 +16,7 @@ class CSSFontFaceRule final : public CSSRule {
     WEB_PLATFORM_OBJECT(CSSFontFaceRule, CSSRule);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSFontFaceRule>> create(JS::Realm&, FontFace&&);
+    [[nodiscard]] static JS::NonnullGCPtr<CSSFontFaceRule> create(JS::Realm&, FontFace&&);
 
     virtual ~CSSFontFaceRule() override = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSImportRule.cpp b/Userland/Libraries/LibWeb/CSS/CSSImportRule.cpp
index 9431043444b..568e2e623b6 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSImportRule.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSImportRule.cpp
@@ -19,10 +19,10 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSImportRule>> CSSImportRule::create(AK::URL url, DOM::Document& document)
+JS::NonnullGCPtr<CSSImportRule> CSSImportRule::create(AK::URL url, DOM::Document& document)
 {
     auto& realm = document.realm();
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CSSImportRule>(realm, move(url), document));
+    return realm.heap().allocate<CSSImportRule>(realm, move(url), document);
 }
 
 CSSImportRule::CSSImportRule(AK::URL url, DOM::Document& document)
diff --git a/Userland/Libraries/LibWeb/CSS/CSSImportRule.h b/Userland/Libraries/LibWeb/CSS/CSSImportRule.h
index c11b07a21a1..9687ca070ef 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSImportRule.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSImportRule.h
@@ -22,7 +22,7 @@ class CSSImportRule final
     WEB_PLATFORM_OBJECT(CSSImportRule, CSSRule);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSImportRule>> create(AK::URL, DOM::Document&);
+    [[nodiscard]] static JS::NonnullGCPtr<CSSImportRule> create(AK::URL, DOM::Document&);
 
     virtual ~CSSImportRule() = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSKeyframeRule.cpp b/Userland/Libraries/LibWeb/CSS/CSSKeyframeRule.cpp
index 3724d46ccc5..cbeb9245834 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSKeyframeRule.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSKeyframeRule.cpp
@@ -11,9 +11,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSKeyframeRule>> CSSKeyframeRule::create(JS::Realm& realm, CSS::Percentage key, Web::CSS::CSSStyleDeclaration& declarations)
+JS::NonnullGCPtr<CSSKeyframeRule> CSSKeyframeRule::create(JS::Realm& realm, CSS::Percentage key, Web::CSS::CSSStyleDeclaration& declarations)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CSSKeyframeRule>(realm, realm, key, declarations));
+    return realm.heap().allocate<CSSKeyframeRule>(realm, realm, key, declarations);
 }
 
 void CSSKeyframeRule::visit_edges(Visitor& visitor)
diff --git a/Userland/Libraries/LibWeb/CSS/CSSKeyframeRule.h b/Userland/Libraries/LibWeb/CSS/CSSKeyframeRule.h
index ba49322c764..36d76a8f5cb 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSKeyframeRule.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSKeyframeRule.h
@@ -20,7 +20,7 @@ class CSSKeyframeRule final : public CSSRule {
     WEB_PLATFORM_OBJECT(CSSKeyframeRule, CSSRule);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSKeyframeRule>> create(JS::Realm& realm, CSS::Percentage key, CSSStyleDeclaration& declarations);
+    static JS::NonnullGCPtr<CSSKeyframeRule> create(JS::Realm&, CSS::Percentage key, CSSStyleDeclaration&);
 
     virtual ~CSSKeyframeRule() = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSKeyframesRule.cpp b/Userland/Libraries/LibWeb/CSS/CSSKeyframesRule.cpp
index a9e7bf25e21..5d9d5fbea4f 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSKeyframesRule.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSKeyframesRule.cpp
@@ -10,9 +10,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSKeyframesRule>> CSSKeyframesRule::create(JS::Realm& realm, AK::FlyString name, Vector<JS::NonnullGCPtr<CSSKeyframeRule>> keyframes)
+JS::NonnullGCPtr<CSSKeyframesRule> CSSKeyframesRule::create(JS::Realm& realm, AK::FlyString name, Vector<JS::NonnullGCPtr<CSSKeyframeRule>> keyframes)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CSSKeyframesRule>(realm, realm, move(name), move(keyframes)));
+    return realm.heap().allocate<CSSKeyframesRule>(realm, realm, move(name), move(keyframes));
 }
 
 void CSSKeyframesRule::visit_edges(Visitor& visitor)
diff --git a/Userland/Libraries/LibWeb/CSS/CSSKeyframesRule.h b/Userland/Libraries/LibWeb/CSS/CSSKeyframesRule.h
index ab074f1b7a1..741287c1288 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSKeyframesRule.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSKeyframesRule.h
@@ -21,7 +21,7 @@ class CSSKeyframesRule final : public CSSRule {
     WEB_PLATFORM_OBJECT(CSSKeyframesRule, CSSRule);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSKeyframesRule>> create(JS::Realm& realm, FlyString name, Vector<JS::NonnullGCPtr<CSSKeyframeRule>> keyframes);
+    [[nodiscard]] static JS::NonnullGCPtr<CSSKeyframesRule> create(JS::Realm&, FlyString name, Vector<JS::NonnullGCPtr<CSSKeyframeRule>>);
 
     virtual ~CSSKeyframesRule() = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSMediaRule.cpp b/Userland/Libraries/LibWeb/CSS/CSSMediaRule.cpp
index 83720bfeccd..b21fcecd062 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSMediaRule.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSMediaRule.cpp
@@ -12,9 +12,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSMediaRule>> CSSMediaRule::create(JS::Realm& realm, MediaList& media_queries, CSSRuleList& rules)
+JS::NonnullGCPtr<CSSMediaRule> CSSMediaRule::create(JS::Realm& realm, MediaList& media_queries, CSSRuleList& rules)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CSSMediaRule>(realm, realm, media_queries, rules));
+    return realm.heap().allocate<CSSMediaRule>(realm, realm, media_queries, rules);
 }
 
 CSSMediaRule::CSSMediaRule(JS::Realm& realm, MediaList& media, CSSRuleList& rules)
diff --git a/Userland/Libraries/LibWeb/CSS/CSSMediaRule.h b/Userland/Libraries/LibWeb/CSS/CSSMediaRule.h
index 492ecc8ace2..ce3a4961685 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSMediaRule.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSMediaRule.h
@@ -18,7 +18,7 @@ class CSSMediaRule final : public CSSConditionRule {
     WEB_PLATFORM_OBJECT(CSSMediaRule, CSSConditionRule);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSMediaRule>> create(JS::Realm&, MediaList& media_queries, CSSRuleList&);
+    [[nodiscard]] static JS::NonnullGCPtr<CSSMediaRule> create(JS::Realm&, MediaList& media_queries, CSSRuleList&);
 
     virtual ~CSSMediaRule() = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSNamespaceRule.cpp b/Userland/Libraries/LibWeb/CSS/CSSNamespaceRule.cpp
index 86f2cf963cd..271098a6e29 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSNamespaceRule.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSNamespaceRule.cpp
@@ -21,9 +21,9 @@ CSSNamespaceRule::CSSNamespaceRule(JS::Realm& realm, Optional<DeprecatedString>
 {
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSNamespaceRule>> CSSNamespaceRule::create(JS::Realm& realm, Optional<DeprecatedString> prefix, AK::StringView namespace_uri)
+JS::NonnullGCPtr<CSSNamespaceRule> CSSNamespaceRule::create(JS::Realm& realm, Optional<DeprecatedString> prefix, AK::StringView namespace_uri)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CSSNamespaceRule>(realm, realm, prefix, namespace_uri));
+    return realm.heap().allocate<CSSNamespaceRule>(realm, realm, prefix, namespace_uri);
 }
 
 void CSSNamespaceRule::initialize(JS::Realm& realm)
diff --git a/Userland/Libraries/LibWeb/CSS/CSSNamespaceRule.h b/Userland/Libraries/LibWeb/CSS/CSSNamespaceRule.h
index 59a1ae1bc4f..42d6adcdb8f 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSNamespaceRule.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSNamespaceRule.h
@@ -14,7 +14,7 @@ class CSSNamespaceRule final : public CSSRule {
     WEB_PLATFORM_OBJECT(CSSNamespaceRule, CSSRule);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSNamespaceRule>> create(JS::Realm&, Optional<DeprecatedString> prefix, StringView namespace_uri);
+    [[nodiscard]] static JS::NonnullGCPtr<CSSNamespaceRule> create(JS::Realm&, Optional<DeprecatedString> prefix, StringView namespace_uri);
 
     virtual ~CSSNamespaceRule() = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSRuleList.cpp b/Userland/Libraries/LibWeb/CSS/CSSRuleList.cpp
index c9172a04bcc..4ab2a040eec 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSRuleList.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSRuleList.cpp
@@ -18,9 +18,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSRuleList>> CSSRuleList::create(JS::Realm& realm, JS::MarkedVector<CSSRule*> const& rules)
+JS::NonnullGCPtr<CSSRuleList> CSSRuleList::create(JS::Realm& realm, JS::MarkedVector<CSSRule*> const& rules)
 {
-    auto rule_list = MUST_OR_THROW_OOM(realm.heap().allocate<CSSRuleList>(realm, realm));
+    auto rule_list = realm.heap().allocate<CSSRuleList>(realm, realm);
     for (auto* rule : rules)
         rule_list->m_rules.append(*rule);
     return rule_list;
@@ -31,9 +31,9 @@ CSSRuleList::CSSRuleList(JS::Realm& realm)
 {
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSRuleList>> CSSRuleList::create_empty(JS::Realm& realm)
+JS::NonnullGCPtr<CSSRuleList> CSSRuleList::create_empty(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CSSRuleList>(realm, realm));
+    return realm.heap().allocate<CSSRuleList>(realm, realm);
 }
 
 void CSSRuleList::initialize(JS::Realm& realm)
diff --git a/Userland/Libraries/LibWeb/CSS/CSSRuleList.h b/Userland/Libraries/LibWeb/CSS/CSSRuleList.h
index 1fcbf9cf6f2..455a9de93c6 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSRuleList.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSRuleList.h
@@ -23,8 +23,8 @@ class CSSRuleList : public Bindings::LegacyPlatformObject {
     WEB_PLATFORM_OBJECT(CSSRuleList, Bindings::LegacyPlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSRuleList>> create(JS::Realm&, JS::MarkedVector<CSSRule*> const&);
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSRuleList>> create_empty(JS::Realm&);
+    [[nodiscard]] static JS::NonnullGCPtr<CSSRuleList> create(JS::Realm&, JS::MarkedVector<CSSRule*> const&);
+    [[nodiscard]] static JS::NonnullGCPtr<CSSRuleList> create_empty(JS::Realm&);
 
     ~CSSRuleList() = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp
index bbd7f8686b9..352f1fee3f6 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp
@@ -26,9 +26,9 @@ void CSSStyleDeclaration::initialize(JS::Realm& realm)
     set_prototype(&Bindings::ensure_web_prototype<Bindings::CSSStyleDeclarationPrototype>(realm, "CSSStyleDeclaration"));
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<PropertyOwningCSSStyleDeclaration>> PropertyOwningCSSStyleDeclaration::create(JS::Realm& realm, Vector<StyleProperty> properties, HashMap<DeprecatedString, StyleProperty> custom_properties)
+JS::NonnullGCPtr<PropertyOwningCSSStyleDeclaration> PropertyOwningCSSStyleDeclaration::create(JS::Realm& realm, Vector<StyleProperty> properties, HashMap<DeprecatedString, StyleProperty> custom_properties)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<PropertyOwningCSSStyleDeclaration>(realm, realm, move(properties), move(custom_properties)));
+    return realm.heap().allocate<PropertyOwningCSSStyleDeclaration>(realm, realm, move(properties), move(custom_properties));
 }
 
 PropertyOwningCSSStyleDeclaration::PropertyOwningCSSStyleDeclaration(JS::Realm& realm, Vector<StyleProperty> properties, HashMap<DeprecatedString, StyleProperty> custom_properties)
@@ -45,10 +45,10 @@ DeprecatedString PropertyOwningCSSStyleDeclaration::item(size_t index) const
     return CSS::string_from_property_id(m_properties[index].property_id);
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<ElementInlineCSSStyleDeclaration>> ElementInlineCSSStyleDeclaration::create(DOM::Element& element, Vector<StyleProperty> properties, HashMap<DeprecatedString, StyleProperty> custom_properties)
+JS::NonnullGCPtr<ElementInlineCSSStyleDeclaration> ElementInlineCSSStyleDeclaration::create(DOM::Element& element, Vector<StyleProperty> properties, HashMap<DeprecatedString, StyleProperty> custom_properties)
 {
     auto& realm = element.realm();
-    return MUST_OR_THROW_OOM(realm.heap().allocate<ElementInlineCSSStyleDeclaration>(realm, element, move(properties), move(custom_properties)));
+    return realm.heap().allocate<ElementInlineCSSStyleDeclaration>(realm, element, move(properties), move(custom_properties));
 }
 
 ElementInlineCSSStyleDeclaration::ElementInlineCSSStyleDeclaration(DOM::Element& element, Vector<StyleProperty> properties, HashMap<DeprecatedString, StyleProperty> custom_properties)
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.h b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
index 9450304f81a..17667389328 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
@@ -53,7 +53,7 @@ class PropertyOwningCSSStyleDeclaration : public CSSStyleDeclaration {
     friend class ElementInlineCSSStyleDeclaration;
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<PropertyOwningCSSStyleDeclaration>>
+    [[nodiscard]] static JS::NonnullGCPtr<PropertyOwningCSSStyleDeclaration>
     create(JS::Realm&, Vector<StyleProperty>, HashMap<DeprecatedString, StyleProperty> custom_properties);
 
     virtual ~PropertyOwningCSSStyleDeclaration() override = default;
@@ -93,7 +93,7 @@ class ElementInlineCSSStyleDeclaration final : public PropertyOwningCSSStyleDecl
     WEB_PLATFORM_OBJECT(ElementInlineCSSStyleDeclaration, PropertyOwningCSSStyleDeclaration);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<ElementInlineCSSStyleDeclaration>> create(DOM::Element&, Vector<StyleProperty> properties, HashMap<DeprecatedString, StyleProperty> custom_properties);
+    [[nodiscard]] static JS::NonnullGCPtr<ElementInlineCSSStyleDeclaration> create(DOM::Element&, Vector<StyleProperty>, HashMap<DeprecatedString, StyleProperty> custom_properties);
 
     virtual ~ElementInlineCSSStyleDeclaration() override = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleRule.cpp b/Userland/Libraries/LibWeb/CSS/CSSStyleRule.cpp
index a8024525c56..dfd52838440 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleRule.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleRule.cpp
@@ -12,9 +12,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSStyleRule>> CSSStyleRule::create(JS::Realm& realm, Vector<NonnullRefPtr<Web::CSS::Selector>>&& selectors, CSSStyleDeclaration& declaration)
+JS::NonnullGCPtr<CSSStyleRule> CSSStyleRule::create(JS::Realm& realm, Vector<NonnullRefPtr<Web::CSS::Selector>>&& selectors, CSSStyleDeclaration& declaration)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CSSStyleRule>(realm, realm, move(selectors), declaration));
+    return realm.heap().allocate<CSSStyleRule>(realm, realm, move(selectors), declaration);
 }
 
 CSSStyleRule::CSSStyleRule(JS::Realm& realm, Vector<NonnullRefPtr<Selector>>&& selectors, CSSStyleDeclaration& declaration)
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleRule.h b/Userland/Libraries/LibWeb/CSS/CSSStyleRule.h
index 44509994928..0a9c57054a8 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleRule.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleRule.h
@@ -18,7 +18,7 @@ class CSSStyleRule final : public CSSRule {
     WEB_PLATFORM_OBJECT(CSSStyleRule, CSSRule);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSStyleRule>> create(JS::Realm&, Vector<NonnullRefPtr<Selector>>&&, CSSStyleDeclaration&);
+    [[nodiscard]] static JS::NonnullGCPtr<CSSStyleRule> create(JS::Realm&, Vector<NonnullRefPtr<Selector>>&&, CSSStyleDeclaration&);
 
     virtual ~CSSStyleRule() override = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleSheet.cpp b/Userland/Libraries/LibWeb/CSS/CSSStyleSheet.cpp
index e3e7b779d87..f0c3ba784dd 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleSheet.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleSheet.cpp
@@ -15,9 +15,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSStyleSheet>> CSSStyleSheet::create(JS::Realm& realm, CSSRuleList& rules, MediaList& media, Optional<AK::URL> location)
+JS::NonnullGCPtr<CSSStyleSheet> CSSStyleSheet::create(JS::Realm& realm, CSSRuleList& rules, MediaList& media, Optional<AK::URL> location)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CSSStyleSheet>(realm, realm, rules, media, move(location)));
+    return realm.heap().allocate<CSSStyleSheet>(realm, realm, rules, media, move(location));
 }
 
 CSSStyleSheet::CSSStyleSheet(JS::Realm& realm, CSSRuleList& rules, MediaList& media, Optional<AK::URL> location)
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleSheet.h b/Userland/Libraries/LibWeb/CSS/CSSStyleSheet.h
index 452a84d7b93..7298ef9e82c 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleSheet.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleSheet.h
@@ -23,7 +23,7 @@ class CSSStyleSheet final
     WEB_PLATFORM_OBJECT(CSSStyleSheet, StyleSheet);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSStyleSheet>> create(JS::Realm&, CSSRuleList& rules, MediaList& media, Optional<AK::URL> location);
+    [[nodiscard]] static JS::NonnullGCPtr<CSSStyleSheet> create(JS::Realm&, CSSRuleList&, MediaList&, Optional<AK::URL> location);
 
     virtual ~CSSStyleSheet() override = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSSupportsRule.cpp b/Userland/Libraries/LibWeb/CSS/CSSSupportsRule.cpp
index ff32ead9100..d318e8d8111 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSSupportsRule.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSSupportsRule.cpp
@@ -11,9 +11,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSSupportsRule>> CSSSupportsRule::create(JS::Realm& realm, NonnullRefPtr<Supports>&& supports, CSSRuleList& rules)
+JS::NonnullGCPtr<CSSSupportsRule> CSSSupportsRule::create(JS::Realm& realm, NonnullRefPtr<Supports>&& supports, CSSRuleList& rules)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CSSSupportsRule>(realm, realm, move(supports), rules));
+    return realm.heap().allocate<CSSSupportsRule>(realm, realm, move(supports), rules);
 }
 
 CSSSupportsRule::CSSSupportsRule(JS::Realm& realm, NonnullRefPtr<Supports>&& supports, CSSRuleList& rules)
diff --git a/Userland/Libraries/LibWeb/CSS/CSSSupportsRule.h b/Userland/Libraries/LibWeb/CSS/CSSSupportsRule.h
index 23f033409a1..acc19052e81 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSSupportsRule.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSSupportsRule.h
@@ -19,7 +19,7 @@ class CSSSupportsRule final : public CSSConditionRule {
     WEB_PLATFORM_OBJECT(CSSSupportsRule, CSSConditionRule);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CSSSupportsRule>> create(JS::Realm&, NonnullRefPtr<Supports>&&, CSSRuleList&);
+    static JS::NonnullGCPtr<CSSSupportsRule> create(JS::Realm&, NonnullRefPtr<Supports>&&, CSSRuleList&);
 
     virtual ~CSSSupportsRule() = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/MediaList.cpp b/Userland/Libraries/LibWeb/CSS/MediaList.cpp
index 26146d7df3c..03bbe397cd7 100644
--- a/Userland/Libraries/LibWeb/CSS/MediaList.cpp
+++ b/Userland/Libraries/LibWeb/CSS/MediaList.cpp
@@ -13,9 +13,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<MediaList>> MediaList::create(JS::Realm& realm, Vector<NonnullRefPtr<MediaQuery>>&& media)
+JS::NonnullGCPtr<MediaList> MediaList::create(JS::Realm& realm, Vector<NonnullRefPtr<MediaQuery>>&& media)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<MediaList>(realm, realm, move(media)));
+    return realm.heap().allocate<MediaList>(realm, realm, move(media));
 }
 
 MediaList::MediaList(JS::Realm& realm, Vector<NonnullRefPtr<MediaQuery>>&& media)
diff --git a/Userland/Libraries/LibWeb/CSS/MediaList.h b/Userland/Libraries/LibWeb/CSS/MediaList.h
index 50788a58bfb..d68a732351c 100644
--- a/Userland/Libraries/LibWeb/CSS/MediaList.h
+++ b/Userland/Libraries/LibWeb/CSS/MediaList.h
@@ -20,7 +20,7 @@ class MediaList final : public Bindings::LegacyPlatformObject {
     WEB_PLATFORM_OBJECT(MediaList, Bindings::LegacyPlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<MediaList>> create(JS::Realm&, Vector<NonnullRefPtr<MediaQuery>>&& media);
+    [[nodiscard]] static JS::NonnullGCPtr<MediaList> create(JS::Realm&, Vector<NonnullRefPtr<MediaQuery>>&&);
     ~MediaList() = default;
 
     DeprecatedString media_text() const;
diff --git a/Userland/Libraries/LibWeb/CSS/MediaQueryList.cpp b/Userland/Libraries/LibWeb/CSS/MediaQueryList.cpp
index 309e39f9293..b306655ad78 100644
--- a/Userland/Libraries/LibWeb/CSS/MediaQueryList.cpp
+++ b/Userland/Libraries/LibWeb/CSS/MediaQueryList.cpp
@@ -15,9 +15,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<MediaQueryList>> MediaQueryList::create(DOM::Document& document, Vector<NonnullRefPtr<MediaQuery>>&& media)
+JS::NonnullGCPtr<MediaQueryList> MediaQueryList::create(DOM::Document& document, Vector<NonnullRefPtr<MediaQuery>>&& media)
 {
-    return MUST_OR_THROW_OOM(document.heap().allocate<MediaQueryList>(document.realm(), document, move(media)));
+    return document.heap().allocate<MediaQueryList>(document.realm(), document, move(media));
 }
 
 MediaQueryList::MediaQueryList(DOM::Document& document, Vector<NonnullRefPtr<MediaQuery>>&& media)
diff --git a/Userland/Libraries/LibWeb/CSS/MediaQueryList.h b/Userland/Libraries/LibWeb/CSS/MediaQueryList.h
index 40f281028f7..d554adf31ae 100644
--- a/Userland/Libraries/LibWeb/CSS/MediaQueryList.h
+++ b/Userland/Libraries/LibWeb/CSS/MediaQueryList.h
@@ -17,7 +17,7 @@ class MediaQueryList final : public DOM::EventTarget {
     WEB_PLATFORM_OBJECT(MediaQueryList, DOM::EventTarget);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<MediaQueryList>> create(DOM::Document&, Vector<NonnullRefPtr<MediaQuery>>&&);
+    [[nodiscard]] static JS::NonnullGCPtr<MediaQueryList> create(DOM::Document&, Vector<NonnullRefPtr<MediaQuery>>&&);
 
     virtual ~MediaQueryList() override = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/MediaQueryListEvent.cpp b/Userland/Libraries/LibWeb/CSS/MediaQueryListEvent.cpp
index bdadffae1cf..137092c4e58 100644
--- a/Userland/Libraries/LibWeb/CSS/MediaQueryListEvent.cpp
+++ b/Userland/Libraries/LibWeb/CSS/MediaQueryListEvent.cpp
@@ -10,9 +10,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<MediaQueryListEvent>> MediaQueryListEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, MediaQueryListEventInit const& event_init)
+JS::NonnullGCPtr<MediaQueryListEvent> MediaQueryListEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, MediaQueryListEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<MediaQueryListEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<MediaQueryListEvent>(realm, realm, event_name, event_init);
 }
 
 MediaQueryListEvent::MediaQueryListEvent(JS::Realm& realm, FlyString const& event_name, MediaQueryListEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/CSS/MediaQueryListEvent.h b/Userland/Libraries/LibWeb/CSS/MediaQueryListEvent.h
index 8e4310bf46b..3dcb7ac41e1 100644
--- a/Userland/Libraries/LibWeb/CSS/MediaQueryListEvent.h
+++ b/Userland/Libraries/LibWeb/CSS/MediaQueryListEvent.h
@@ -20,7 +20,7 @@ class MediaQueryListEvent final : public DOM::Event {
     WEB_PLATFORM_OBJECT(MediaQueryListEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<MediaQueryListEvent>> construct_impl(JS::Realm&, FlyString const& event_name, MediaQueryListEventInit const& event_init = {});
+    [[nodiscard]] static JS::NonnullGCPtr<MediaQueryListEvent> construct_impl(JS::Realm&, FlyString const& event_name, MediaQueryListEventInit const& = {});
 
     virtual ~MediaQueryListEvent() override;
 
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/Helpers.cpp b/Userland/Libraries/LibWeb/CSS/Parser/Helpers.cpp
index 1515e75f777..362a40c385f 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/Helpers.cpp
+++ b/Userland/Libraries/LibWeb/CSS/Parser/Helpers.cpp
@@ -18,9 +18,9 @@ namespace Web {
 CSS::CSSStyleSheet* parse_css_stylesheet(CSS::Parser::ParsingContext const& context, StringView css, Optional<AK::URL> location)
 {
     if (css.is_empty()) {
-        auto rule_list = CSS::CSSRuleList::create_empty(context.realm()).release_value_but_fixme_should_propagate_errors();
-        auto media_list = CSS::MediaList::create(context.realm(), {}).release_value_but_fixme_should_propagate_errors();
-        return CSS::CSSStyleSheet::create(context.realm(), rule_list, media_list, location).release_value_but_fixme_should_propagate_errors();
+        auto rule_list = CSS::CSSRuleList::create_empty(context.realm());
+        auto media_list = CSS::MediaList::create(context.realm(), {});
+        return CSS::CSSStyleSheet::create(context.realm(), rule_list, media_list, location);
     }
     auto parser = CSS::Parser::Parser::create(context, css).release_value_but_fixme_should_propagate_errors();
     return parser.parse_as_css_stylesheet(location);
@@ -29,7 +29,7 @@ CSS::CSSStyleSheet* parse_css_stylesheet(CSS::Parser::ParsingContext const& cont
 CSS::ElementInlineCSSStyleDeclaration* parse_css_style_attribute(CSS::Parser::ParsingContext const& context, StringView css, DOM::Element& element)
 {
     if (css.is_empty())
-        return CSS::ElementInlineCSSStyleDeclaration::create(element, {}, {}).release_value_but_fixme_should_propagate_errors();
+        return CSS::ElementInlineCSSStyleDeclaration::create(element, {}, {});
     auto parser = CSS::Parser::Parser::create(context, css).release_value_but_fixme_should_propagate_errors();
     return parser.parse_as_style_attribute(element);
 }
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp b/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
index ae2d19718d4..0f9c4a6d605 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
+++ b/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
@@ -161,9 +161,9 @@ CSSStyleSheet* Parser::parse_as_css_stylesheet(Optional<AK::URL> location)
             rules.append(rule);
     }
 
-    auto rule_list = CSSRuleList::create(m_context.realm(), rules).release_value_but_fixme_should_propagate_errors();
-    auto media_list = MediaList::create(m_context.realm(), {}).release_value_but_fixme_should_propagate_errors();
-    return CSSStyleSheet::create(m_context.realm(), rule_list, media_list, move(location)).release_value_but_fixme_should_propagate_errors();
+    auto rule_list = CSSRuleList::create(m_context.realm(), rules);
+    auto media_list = MediaList::create(m_context.realm(), {});
+    return CSSStyleSheet::create(m_context.realm(), rule_list, media_list, move(location));
 }
 
 Optional<SelectorList> Parser::parse_as_selector(SelectorParsingMode parsing_mode)
@@ -2360,7 +2360,7 @@ ElementInlineCSSStyleDeclaration* Parser::parse_as_style_attribute(DOM::Element&
 {
     auto declarations_and_at_rules = parse_a_list_of_declarations(m_token_stream);
     auto [properties, custom_properties] = extract_properties(declarations_and_at_rules);
-    return ElementInlineCSSStyleDeclaration::create(element, move(properties), move(custom_properties)).release_value_but_fixme_should_propagate_errors();
+    return ElementInlineCSSStyleDeclaration::create(element, move(properties), move(custom_properties));
 }
 
 Optional<AK::URL> Parser::parse_url_function(ComponentValue const& component_value)
@@ -3149,7 +3149,7 @@ CSSRule* Parser::convert_to_rule(NonnullRefPtr<Rule> rule)
             }
 
             if (url.has_value())
-                return CSSImportRule::create(url.value(), const_cast<DOM::Document&>(*m_context.document())).release_value_but_fixme_should_propagate_errors();
+                return CSSImportRule::create(url.value(), const_cast<DOM::Document&>(*m_context.document()));
             dbgln_if(CSS_PARSER_DEBUG, "Unable to parse url from @import rule");
             return {};
         }
@@ -3166,9 +3166,9 @@ CSSRule* Parser::convert_to_rule(NonnullRefPtr<Rule> rule)
                 if (auto* child_rule = convert_to_rule(raw_rule))
                     child_rules.append(child_rule);
             }
-            auto media_list = MediaList::create(m_context.realm(), move(media_query_list)).release_value_but_fixme_should_propagate_errors();
-            auto rule_list = CSSRuleList::create(m_context.realm(), child_rules).release_value_but_fixme_should_propagate_errors();
-            return CSSMediaRule::create(m_context.realm(), media_list, rule_list).release_value_but_fixme_should_propagate_errors();
+            auto media_list = MediaList::create(m_context.realm(), move(media_query_list));
+            auto rule_list = CSSRuleList::create(m_context.realm(), child_rules);
+            return CSSMediaRule::create(m_context.realm(), media_list, rule_list);
         }
         if (rule->at_rule_name().equals_ignoring_ascii_case("supports"sv)) {
             auto supports_tokens = TokenStream { rule->prelude() };
@@ -3191,8 +3191,8 @@ CSSRule* Parser::convert_to_rule(NonnullRefPtr<Rule> rule)
                     child_rules.append(child_rule);
             }
 
-            auto rule_list = CSSRuleList::create(m_context.realm(), child_rules).release_value_but_fixme_should_propagate_errors();
-            return CSSSupportsRule::create(m_context.realm(), supports.release_nonnull(), rule_list).release_value_but_fixme_should_propagate_errors();
+            auto rule_list = CSSRuleList::create(m_context.realm(), child_rules);
+            return CSSSupportsRule::create(m_context.realm(), supports.release_nonnull(), rule_list);
         }
         if (rule->at_rule_name().equals_ignoring_ascii_case("keyframes"sv)) {
             auto prelude_stream = TokenStream { rule->prelude() };
@@ -3286,7 +3286,7 @@ CSSRule* Parser::convert_to_rule(NonnullRefPtr<Rule> rule)
                     auto block_declarations = parse_a_list_of_declarations(block_stream);
                     auto style = convert_to_style_declaration(block_declarations);
                     for (auto& selector : selectors) {
-                        auto keyframe_rule = CSSKeyframeRule::create(m_context.realm(), selector, *style).release_value_but_fixme_should_propagate_errors();
+                        auto keyframe_rule = CSSKeyframeRule::create(m_context.realm(), selector, *style);
                         keyframes.append(keyframe_rule);
                     }
                 } else {
@@ -3294,7 +3294,7 @@ CSSRule* Parser::convert_to_rule(NonnullRefPtr<Rule> rule)
                 }
             }
 
-            return CSSKeyframesRule::create(m_context.realm(), name, move(keyframes)).release_value_but_fixme_should_propagate_errors();
+            return CSSKeyframesRule::create(m_context.realm(), name, move(keyframes));
         }
         if (rule->at_rule_name().equals_ignoring_ascii_case("namespace"sv)) {
             // https://drafts.csswg.org/css-namespaces/#syntax
@@ -3325,7 +3325,7 @@ CSSRule* Parser::convert_to_rule(NonnullRefPtr<Rule> rule)
                 return {};
             }
 
-            return CSSNamespaceRule::create(m_context.realm(), prefix, namespace_uri).release_value_but_fixme_should_propagate_errors();
+            return CSSNamespaceRule::create(m_context.realm(), prefix, namespace_uri);
         }
 
         // FIXME: More at rules!
@@ -3363,7 +3363,7 @@ CSSRule* Parser::convert_to_rule(NonnullRefPtr<Rule> rule)
         return {};
     }
 
-    return CSSStyleRule::create(m_context.realm(), move(selectors.value()), *declaration).release_value_but_fixme_should_propagate_errors();
+    return CSSStyleRule::create(m_context.realm(), move(selectors.value()), *declaration);
 }
 
 auto Parser::extract_properties(Vector<DeclarationOrAtRule> const& declarations_and_at_rules) -> PropertiesAndCustomProperties
@@ -3392,7 +3392,7 @@ auto Parser::extract_properties(Vector<DeclarationOrAtRule> const& declarations_
 PropertyOwningCSSStyleDeclaration* Parser::convert_to_style_declaration(Vector<DeclarationOrAtRule> const& declarations_and_at_rules)
 {
     auto [properties, custom_properties] = extract_properties(declarations_and_at_rules);
-    return PropertyOwningCSSStyleDeclaration::create(m_context.realm(), move(properties), move(custom_properties)).release_value_but_fixme_should_propagate_errors();
+    return PropertyOwningCSSStyleDeclaration::create(m_context.realm(), move(properties), move(custom_properties));
 }
 
 Optional<StyleProperty> Parser::convert_to_style_property(Declaration const& declaration)
@@ -6133,7 +6133,7 @@ CSSRule* Parser::parse_font_face_rule(TokenStream<ComponentValue>& tokens)
         unicode_range.empend(0x0u, 0x10FFFFu);
     }
 
-    return CSSFontFaceRule::create(m_context.realm(), FontFace { font_family.release_value(), weight, slope, move(src), move(unicode_range) }).release_value_but_fixme_should_propagate_errors();
+    return CSSFontFaceRule::create(m_context.realm(), FontFace { font_family.release_value(), weight, slope, move(src), move(unicode_range) });
 }
 
 Vector<FontFace::Source> Parser::parse_font_face_src(TokenStream<ComponentValue>& component_values)
diff --git a/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.cpp b/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.cpp
index 638c0e333ef..92b25d447ff 100644
--- a/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.cpp
+++ b/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.cpp
@@ -48,9 +48,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<ResolvedCSSStyleDeclaration>> ResolvedCSSStyleDeclaration::create(DOM::Element& element)
+JS::NonnullGCPtr<ResolvedCSSStyleDeclaration> ResolvedCSSStyleDeclaration::create(DOM::Element& element)
 {
-    return MUST_OR_THROW_OOM(element.realm().heap().allocate<ResolvedCSSStyleDeclaration>(element.realm(), element));
+    return element.realm().heap().allocate<ResolvedCSSStyleDeclaration>(element.realm(), element);
 }
 
 ResolvedCSSStyleDeclaration::ResolvedCSSStyleDeclaration(DOM::Element& element)
diff --git a/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h b/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h
index f5bc44bbf57..93a367f7af3 100644
--- a/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h
+++ b/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h
@@ -14,7 +14,7 @@ class ResolvedCSSStyleDeclaration final : public CSSStyleDeclaration {
     WEB_PLATFORM_OBJECT(ResolvedCSSStyleDeclaration, CSSStyleDeclaration);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<ResolvedCSSStyleDeclaration>> create(DOM::Element& element);
+    [[nodiscard]] static JS::NonnullGCPtr<ResolvedCSSStyleDeclaration> create(DOM::Element&);
 
     virtual ~ResolvedCSSStyleDeclaration() override = default;
 
diff --git a/Userland/Libraries/LibWeb/CSS/Screen.cpp b/Userland/Libraries/LibWeb/CSS/Screen.cpp
index 087244286fd..2533ceae2c5 100644
--- a/Userland/Libraries/LibWeb/CSS/Screen.cpp
+++ b/Userland/Libraries/LibWeb/CSS/Screen.cpp
@@ -13,9 +13,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Screen>> Screen::create(HTML::Window& window)
+JS::NonnullGCPtr<Screen> Screen::create(HTML::Window& window)
 {
-    return MUST_OR_THROW_OOM(window.heap().allocate<Screen>(window.realm(), window));
+    return window.heap().allocate<Screen>(window.realm(), window);
 }
 
 Screen::Screen(HTML::Window& window)
diff --git a/Userland/Libraries/LibWeb/CSS/Screen.h b/Userland/Libraries/LibWeb/CSS/Screen.h
index 9f8ec1d165d..a416576e468 100644
--- a/Userland/Libraries/LibWeb/CSS/Screen.h
+++ b/Userland/Libraries/LibWeb/CSS/Screen.h
@@ -17,7 +17,7 @@ class Screen final : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(Screen, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Screen>> create(HTML::Window&);
+    [[nodiscard]] static JS::NonnullGCPtr<Screen> create(HTML::Window&);
 
     i32 width() const { return screen_rect().width(); }
     i32 height() const { return screen_rect().height(); }
diff --git a/Userland/Libraries/LibWeb/CSS/StyleSheetList.cpp b/Userland/Libraries/LibWeb/CSS/StyleSheetList.cpp
index 2d2805ad31a..ce01e8e3445 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleSheetList.cpp
+++ b/Userland/Libraries/LibWeb/CSS/StyleSheetList.cpp
@@ -62,10 +62,10 @@ void StyleSheetList::remove_sheet(CSSStyleSheet& sheet)
     m_document->invalidate_style();
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<StyleSheetList>> StyleSheetList::create(DOM::Document& document)
+JS::NonnullGCPtr<StyleSheetList> StyleSheetList::create(DOM::Document& document)
 {
     auto& realm = document.realm();
-    return MUST_OR_THROW_OOM(realm.heap().allocate<StyleSheetList>(realm, document));
+    return realm.heap().allocate<StyleSheetList>(realm, document);
 }
 
 StyleSheetList::StyleSheetList(DOM::Document& document)
diff --git a/Userland/Libraries/LibWeb/CSS/StyleSheetList.h b/Userland/Libraries/LibWeb/CSS/StyleSheetList.h
index 455ad6ed589..5cdc22d7f7d 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleSheetList.h
+++ b/Userland/Libraries/LibWeb/CSS/StyleSheetList.h
@@ -16,7 +16,7 @@ class StyleSheetList : public Bindings::LegacyPlatformObject {
     WEB_PLATFORM_OBJECT(StyleSheetList, Bindings::LegacyPlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<StyleSheetList>> create(DOM::Document& document);
+    [[nodiscard]] static JS::NonnullGCPtr<StyleSheetList> create(DOM::Document&);
 
     void add_sheet(CSSStyleSheet&);
     void remove_sheet(CSSStyleSheet&);
diff --git a/Userland/Libraries/LibWeb/CSS/VisualViewport.cpp b/Userland/Libraries/LibWeb/CSS/VisualViewport.cpp
index 92cb7d0422e..0afa19e7279 100644
--- a/Userland/Libraries/LibWeb/CSS/VisualViewport.cpp
+++ b/Userland/Libraries/LibWeb/CSS/VisualViewport.cpp
@@ -15,9 +15,9 @@
 
 namespace Web::CSS {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<VisualViewport>> VisualViewport::create(DOM::Document& document)
+JS::NonnullGCPtr<VisualViewport> VisualViewport::create(DOM::Document& document)
 {
-    return MUST_OR_THROW_OOM(document.heap().allocate<VisualViewport>(document.realm(), document));
+    return document.heap().allocate<VisualViewport>(document.realm(), document);
 }
 
 VisualViewport::VisualViewport(DOM::Document& document)
diff --git a/Userland/Libraries/LibWeb/CSS/VisualViewport.h b/Userland/Libraries/LibWeb/CSS/VisualViewport.h
index 19d14539007..c471bb7fe44 100644
--- a/Userland/Libraries/LibWeb/CSS/VisualViewport.h
+++ b/Userland/Libraries/LibWeb/CSS/VisualViewport.h
@@ -15,7 +15,7 @@ class VisualViewport final : public DOM::EventTarget {
     WEB_PLATFORM_OBJECT(VisualViewport, DOM::EventTarget);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<VisualViewport>> create(DOM::Document&);
+    [[nodiscard]] static JS::NonnullGCPtr<VisualViewport> create(DOM::Document&);
 
     virtual ~VisualViewport() override = default;
 
diff --git a/Userland/Libraries/LibWeb/Crypto/Crypto.cpp b/Userland/Libraries/LibWeb/Crypto/Crypto.cpp
index 1666df5535d..17d9fc380e5 100644
--- a/Userland/Libraries/LibWeb/Crypto/Crypto.cpp
+++ b/Userland/Libraries/LibWeb/Crypto/Crypto.cpp
@@ -15,9 +15,9 @@
 
 namespace Web::Crypto {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Crypto>> Crypto::create(JS::Realm& realm)
+JS::NonnullGCPtr<Crypto> Crypto::create(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Crypto>(realm, realm));
+    return realm.heap().allocate<Crypto>(realm, realm);
 }
 
 Crypto::Crypto(JS::Realm& realm)
@@ -31,7 +31,7 @@ void Crypto::initialize(JS::Realm& realm)
 {
     Base::initialize(realm);
     set_prototype(&Bindings::ensure_web_prototype<Bindings::CryptoPrototype>(realm, "Crypto"));
-    m_subtle = MUST(SubtleCrypto::create(realm));
+    m_subtle = SubtleCrypto::create(realm);
 }
 
 JS::NonnullGCPtr<SubtleCrypto> Crypto::subtle() const
diff --git a/Userland/Libraries/LibWeb/Crypto/Crypto.h b/Userland/Libraries/LibWeb/Crypto/Crypto.h
index 74d3c002fc2..bfb6fb34406 100644
--- a/Userland/Libraries/LibWeb/Crypto/Crypto.h
+++ b/Userland/Libraries/LibWeb/Crypto/Crypto.h
@@ -16,7 +16,7 @@ class Crypto : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(Crypto, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Crypto>> create(JS::Realm&);
+    [[nodiscard]] static JS::NonnullGCPtr<Crypto> create(JS::Realm&);
 
     virtual ~Crypto() override;
 
diff --git a/Userland/Libraries/LibWeb/Crypto/SubtleCrypto.cpp b/Userland/Libraries/LibWeb/Crypto/SubtleCrypto.cpp
index a419e4f16b6..97b9dd29869 100644
--- a/Userland/Libraries/LibWeb/Crypto/SubtleCrypto.cpp
+++ b/Userland/Libraries/LibWeb/Crypto/SubtleCrypto.cpp
@@ -14,9 +14,9 @@
 
 namespace Web::Crypto {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<SubtleCrypto>> SubtleCrypto::create(JS::Realm& realm)
+JS::NonnullGCPtr<SubtleCrypto> SubtleCrypto::create(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<SubtleCrypto>(realm, realm));
+    return realm.heap().allocate<SubtleCrypto>(realm, realm);
 }
 
 SubtleCrypto::SubtleCrypto(JS::Realm& realm)
diff --git a/Userland/Libraries/LibWeb/Crypto/SubtleCrypto.h b/Userland/Libraries/LibWeb/Crypto/SubtleCrypto.h
index 4f95682396f..42203505ccc 100644
--- a/Userland/Libraries/LibWeb/Crypto/SubtleCrypto.h
+++ b/Userland/Libraries/LibWeb/Crypto/SubtleCrypto.h
@@ -15,7 +15,7 @@ class SubtleCrypto final : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(SubtleCrypto, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<SubtleCrypto>> create(JS::Realm&);
+    [[nodiscard]] static JS::NonnullGCPtr<SubtleCrypto> create(JS::Realm&);
 
     virtual ~SubtleCrypto() override;
 
diff --git a/Userland/Libraries/LibWeb/DOM/AbortController.cpp b/Userland/Libraries/LibWeb/DOM/AbortController.cpp
index 3c99d8e5ff8..22cadee5bd1 100644
--- a/Userland/Libraries/LibWeb/DOM/AbortController.cpp
+++ b/Userland/Libraries/LibWeb/DOM/AbortController.cpp
@@ -13,7 +13,7 @@ namespace Web::DOM {
 WebIDL::ExceptionOr<JS::NonnullGCPtr<AbortController>> AbortController::construct_impl(JS::Realm& realm)
 {
     auto signal = TRY(AbortSignal::construct_impl(realm));
-    return MUST_OR_THROW_OOM(realm.heap().allocate<AbortController>(realm, realm, move(signal)));
+    return realm.heap().allocate<AbortController>(realm, realm, move(signal));
 }
 
 // https://dom.spec.whatwg.org/#dom-abortcontroller-abortcontroller
diff --git a/Userland/Libraries/LibWeb/DOM/AbortSignal.cpp b/Userland/Libraries/LibWeb/DOM/AbortSignal.cpp
index 3664198f555..a6b22b15fed 100644
--- a/Userland/Libraries/LibWeb/DOM/AbortSignal.cpp
+++ b/Userland/Libraries/LibWeb/DOM/AbortSignal.cpp
@@ -14,7 +14,7 @@ namespace Web::DOM {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<AbortSignal>> AbortSignal::construct_impl(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<AbortSignal>(realm, realm));
+    return realm.heap().allocate<AbortSignal>(realm, realm);
 }
 
 AbortSignal::AbortSignal(JS::Realm& realm)
@@ -60,7 +60,7 @@ void AbortSignal::signal_abort(JS::Value reason)
     m_abort_algorithms.clear();
 
     // 5. Fire an event named abort at signal.
-    dispatch_event(Event::create(realm(), HTML::EventNames::abort).release_value_but_fixme_should_propagate_errors());
+    dispatch_event(Event::create(realm(), HTML::EventNames::abort));
 }
 
 void AbortSignal::set_onabort(WebIDL::CallbackType* event_handler)
diff --git a/Userland/Libraries/LibWeb/DOM/AccessibilityTreeNode.cpp b/Userland/Libraries/LibWeb/DOM/AccessibilityTreeNode.cpp
index 263d67b94ca..10734964242 100644
--- a/Userland/Libraries/LibWeb/DOM/AccessibilityTreeNode.cpp
+++ b/Userland/Libraries/LibWeb/DOM/AccessibilityTreeNode.cpp
@@ -13,9 +13,9 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<AccessibilityTreeNode>> AccessibilityTreeNode::create(Document* document, DOM::Node const* value)
+JS::NonnullGCPtr<AccessibilityTreeNode> AccessibilityTreeNode::create(Document* document, DOM::Node const* value)
 {
-    return MUST_OR_THROW_OOM(document->heap().allocate<AccessibilityTreeNode>(document->realm(), value));
+    return document->heap().allocate<AccessibilityTreeNode>(document->realm(), value);
 }
 
 AccessibilityTreeNode::AccessibilityTreeNode(JS::GCPtr<DOM::Node const> value)
diff --git a/Userland/Libraries/LibWeb/DOM/AccessibilityTreeNode.h b/Userland/Libraries/LibWeb/DOM/AccessibilityTreeNode.h
index d2f1ee24e70..9b7301b3c88 100644
--- a/Userland/Libraries/LibWeb/DOM/AccessibilityTreeNode.h
+++ b/Userland/Libraries/LibWeb/DOM/AccessibilityTreeNode.h
@@ -17,7 +17,7 @@ namespace Web::DOM {
 class AccessibilityTreeNode final : public JS::Cell {
     JS_CELL(AccessibilityTreeNode, JS::Cell)
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<AccessibilityTreeNode>> create(Document*, DOM::Node const*);
+    static JS::NonnullGCPtr<AccessibilityTreeNode> create(Document*, DOM::Node const*);
     virtual ~AccessibilityTreeNode() override = default;
 
     JS::GCPtr<DOM::Node const> value() const { return m_value; }
diff --git a/Userland/Libraries/LibWeb/DOM/Attr.cpp b/Userland/Libraries/LibWeb/DOM/Attr.cpp
index a0148bb65d8..152344a7e8a 100644
--- a/Userland/Libraries/LibWeb/DOM/Attr.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Attr.cpp
@@ -15,19 +15,19 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Attr>> Attr::create(Document& document, DeprecatedFlyString local_name, DeprecatedString value, Element* owner_element)
+JS::NonnullGCPtr<Attr> Attr::create(Document& document, DeprecatedFlyString local_name, DeprecatedString value, Element* owner_element)
 {
-    return MUST_OR_THROW_OOM(document.heap().allocate<Attr>(document.realm(), document, QualifiedName(move(local_name), {}, {}), move(value), owner_element));
+    return document.heap().allocate<Attr>(document.realm(), document, QualifiedName(move(local_name), {}, {}), move(value), owner_element);
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Attr>> Attr::create(Document& document, QualifiedName qualified_name, DeprecatedString value, Element* owner_element)
+JS::NonnullGCPtr<Attr> Attr::create(Document& document, QualifiedName qualified_name, DeprecatedString value, Element* owner_element)
 {
-    return MUST_OR_THROW_OOM(document.heap().allocate<Attr>(document.realm(), document, move(qualified_name), move(value), owner_element));
+    return document.heap().allocate<Attr>(document.realm(), document, move(qualified_name), move(value), owner_element);
 }
 
 JS::NonnullGCPtr<Attr> Attr::clone(Document& document)
 {
-    return *heap().allocate<Attr>(realm(), document, m_qualified_name, m_value, nullptr).release_allocated_value_but_fixme_should_propagate_errors();
+    return *heap().allocate<Attr>(realm(), document, m_qualified_name, m_value, nullptr);
 }
 
 Attr::Attr(Document& document, QualifiedName qualified_name, DeprecatedString value, Element* owner_element)
diff --git a/Userland/Libraries/LibWeb/DOM/Attr.h b/Userland/Libraries/LibWeb/DOM/Attr.h
index 5ba24c6095d..4d171c04e1c 100644
--- a/Userland/Libraries/LibWeb/DOM/Attr.h
+++ b/Userland/Libraries/LibWeb/DOM/Attr.h
@@ -18,8 +18,8 @@ class Attr final : public Node {
     WEB_PLATFORM_OBJECT(Attr, Node);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Attr>> create(Document&, QualifiedName, DeprecatedString value = "", Element* = nullptr);
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Attr>> create(Document&, DeprecatedFlyString local_name, DeprecatedString value = "", Element* = nullptr);
+    [[nodiscard]] static JS::NonnullGCPtr<Attr> create(Document&, QualifiedName, DeprecatedString value = "", Element* = nullptr);
+    [[nodiscard]] static JS::NonnullGCPtr<Attr> create(Document&, DeprecatedFlyString local_name, DeprecatedString value = "", Element* = nullptr);
     JS::NonnullGCPtr<Attr> clone(Document&);
 
     virtual ~Attr() override = default;
diff --git a/Userland/Libraries/LibWeb/DOM/Comment.cpp b/Userland/Libraries/LibWeb/DOM/Comment.cpp
index ebf250cd9e5..4bb02c55ec2 100644
--- a/Userland/Libraries/LibWeb/DOM/Comment.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Comment.cpp
@@ -20,7 +20,7 @@ Comment::Comment(Document& document, DeprecatedString const& data)
 WebIDL::ExceptionOr<JS::NonnullGCPtr<Comment>> Comment::construct_impl(JS::Realm& realm, DeprecatedString const& data)
 {
     auto& window = verify_cast<HTML::Window>(realm.global_object());
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Comment>(realm, window.associated_document(), data));
+    return realm.heap().allocate<Comment>(realm, window.associated_document(), data);
 }
 
 void Comment::initialize(JS::Realm& realm)
diff --git a/Userland/Libraries/LibWeb/DOM/CustomEvent.cpp b/Userland/Libraries/LibWeb/DOM/CustomEvent.cpp
index 6684dc164c9..5f9e2ec2755 100644
--- a/Userland/Libraries/LibWeb/DOM/CustomEvent.cpp
+++ b/Userland/Libraries/LibWeb/DOM/CustomEvent.cpp
@@ -11,9 +11,9 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CustomEvent>> CustomEvent::create(JS::Realm& realm, FlyString const& event_name, CustomEventInit const& event_init)
+JS::NonnullGCPtr<CustomEvent> CustomEvent::create(JS::Realm& realm, FlyString const& event_name, CustomEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CustomEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<CustomEvent>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<CustomEvent>> CustomEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, CustomEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/DOM/CustomEvent.h b/Userland/Libraries/LibWeb/DOM/CustomEvent.h
index 3fd62c5f557..9c92bfa4b9f 100644
--- a/Userland/Libraries/LibWeb/DOM/CustomEvent.h
+++ b/Userland/Libraries/LibWeb/DOM/CustomEvent.h
@@ -21,8 +21,8 @@ class CustomEvent : public Event {
     WEB_PLATFORM_OBJECT(CustomEvent, Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CustomEvent>> create(JS::Realm&, FlyString const& event_name, CustomEventInit const& event_init = {});
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CustomEvent>> construct_impl(JS::Realm&, FlyString const& event_name, CustomEventInit const& event_init);
+    [[nodiscard]] static JS::NonnullGCPtr<CustomEvent> create(JS::Realm&, FlyString const& event_name, CustomEventInit const& = {});
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CustomEvent>> construct_impl(JS::Realm&, FlyString const& event_name, CustomEventInit const&);
 
     virtual ~CustomEvent() override;
 
diff --git a/Userland/Libraries/LibWeb/DOM/DOMImplementation.cpp b/Userland/Libraries/LibWeb/DOM/DOMImplementation.cpp
index 1fb91d5d5a2..4af9e169634 100644
--- a/Userland/Libraries/LibWeb/DOM/DOMImplementation.cpp
+++ b/Userland/Libraries/LibWeb/DOM/DOMImplementation.cpp
@@ -17,10 +17,10 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMImplementation>> DOMImplementation::create(Document& document)
+JS::NonnullGCPtr<DOMImplementation> DOMImplementation::create(Document& document)
 {
     auto& realm = document.realm();
-    return MUST_OR_THROW_OOM(realm.heap().allocate<DOMImplementation>(realm, document));
+    return realm.heap().allocate<DOMImplementation>(realm, document);
 }
 
 DOMImplementation::DOMImplementation(Document& document)
@@ -47,7 +47,7 @@ void DOMImplementation::visit_edges(Cell::Visitor& visitor)
 WebIDL::ExceptionOr<JS::NonnullGCPtr<Document>> DOMImplementation::create_document(DeprecatedString const& namespace_, DeprecatedString const& qualified_name, JS::GCPtr<DocumentType> doctype) const
 {
     // FIXME: This should specifically be an XML document.
-    auto xml_document = TRY(Document::create(realm()));
+    auto xml_document = Document::create(realm());
 
     xml_document->set_ready_for_post_load_tasks(true);
 
@@ -77,12 +77,12 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Document>> DOMImplementation::create_docume
 // https://dom.spec.whatwg.org/#dom-domimplementation-createhtmldocument
 JS::NonnullGCPtr<Document> DOMImplementation::create_html_document(DeprecatedString const& title) const
 {
-    auto html_document = Document::create(realm()).release_value_but_fixme_should_propagate_errors();
+    auto html_document = Document::create(realm());
 
     html_document->set_content_type("text/html");
     html_document->set_ready_for_post_load_tasks(true);
 
-    auto doctype = heap().allocate<DocumentType>(realm(), html_document).release_allocated_value_but_fixme_should_propagate_errors();
+    auto doctype = heap().allocate<DocumentType>(realm(), html_document);
     doctype->set_name("html");
     MUST(html_document->append_child(*doctype));
 
@@ -96,7 +96,7 @@ JS::NonnullGCPtr<Document> DOMImplementation::create_html_document(DeprecatedStr
         auto title_element = create_element(html_document, HTML::TagNames::title, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
         MUST(head_element->append_child(title_element));
 
-        auto text_node = heap().allocate<Text>(realm(), html_document, title).release_allocated_value_but_fixme_should_propagate_errors();
+        auto text_node = heap().allocate<Text>(realm(), html_document, title);
         MUST(title_element->append_child(*text_node));
     }
 
@@ -112,7 +112,7 @@ JS::NonnullGCPtr<Document> DOMImplementation::create_html_document(DeprecatedStr
 WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentType>> DOMImplementation::create_document_type(DeprecatedString const& qualified_name, DeprecatedString const& public_id, DeprecatedString const& system_id)
 {
     TRY(Document::validate_qualified_name(realm(), qualified_name));
-    auto document_type = TRY(DocumentType::create(document()));
+    auto document_type = DocumentType::create(document());
     document_type->set_name(qualified_name);
     document_type->set_public_id(public_id);
     document_type->set_system_id(system_id);
diff --git a/Userland/Libraries/LibWeb/DOM/DOMImplementation.h b/Userland/Libraries/LibWeb/DOM/DOMImplementation.h
index 2f56d89cdb0..410bf623aa7 100644
--- a/Userland/Libraries/LibWeb/DOM/DOMImplementation.h
+++ b/Userland/Libraries/LibWeb/DOM/DOMImplementation.h
@@ -17,7 +17,7 @@ class DOMImplementation final : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(DOMImplementation, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMImplementation>> create(Document&);
+    [[nodiscard]] static JS::NonnullGCPtr<DOMImplementation> create(Document&);
     virtual ~DOMImplementation();
 
     WebIDL::ExceptionOr<JS::NonnullGCPtr<Document>> create_document(DeprecatedString const&, DeprecatedString const&, JS::GCPtr<DocumentType>) const;
diff --git a/Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp b/Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp
index 8dc2ae9fe45..6acc4555ca2 100644
--- a/Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp
+++ b/Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp
@@ -52,10 +52,10 @@ inline void replace_in_ordered_set(Vector<DeprecatedString>& set, StringView ite
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMTokenList>> DOMTokenList::create(Element& associated_element, DeprecatedFlyString associated_attribute)
+JS::NonnullGCPtr<DOMTokenList> DOMTokenList::create(Element& associated_element, DeprecatedFlyString associated_attribute)
 {
     auto& realm = associated_element.realm();
-    return MUST_OR_THROW_OOM(realm.heap().allocate<DOMTokenList>(realm, associated_element, move(associated_attribute)));
+    return realm.heap().allocate<DOMTokenList>(realm, associated_element, move(associated_attribute));
 }
 
 // https://dom.spec.whatwg.org/#ref-for-domtokenlist%E2%91%A0%E2%91%A2
diff --git a/Userland/Libraries/LibWeb/DOM/DOMTokenList.h b/Userland/Libraries/LibWeb/DOM/DOMTokenList.h
index 798e266d50d..3bc06b62b95 100644
--- a/Userland/Libraries/LibWeb/DOM/DOMTokenList.h
+++ b/Userland/Libraries/LibWeb/DOM/DOMTokenList.h
@@ -24,7 +24,7 @@ class DOMTokenList final : public Bindings::LegacyPlatformObject {
     WEB_PLATFORM_OBJECT(DOMTokenList, Bindings::LegacyPlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMTokenList>> create(Element& associated_element, DeprecatedFlyString associated_attribute);
+    [[nodiscard]] static JS::NonnullGCPtr<DOMTokenList> create(Element& associated_element, DeprecatedFlyString associated_attribute);
     ~DOMTokenList() = default;
 
     void associated_attribute_changed(StringView value);
diff --git a/Userland/Libraries/LibWeb/DOM/Document.cpp b/Userland/Libraries/LibWeb/DOM/Document.cpp
index 358e59e035a..3706b556a3b 100644
--- a/Userland/Libraries/LibWeb/DOM/Document.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Document.cpp
@@ -200,7 +200,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Document>> Document::create_and_initialize(
             Bindings::main_thread_vm(),
             [&](JS::Realm& realm) -> JS::Object* {
                 // - For the global object, create a new Window object.
-                window = HTML::Window::create(realm).release_value_but_fixme_should_propagate_errors();
+                window = HTML::Window::create(realm);
                 return window;
             },
             [&](JS::Realm&) -> JS::Object* {
@@ -232,12 +232,12 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Document>> Document::create_and_initialize(
 
         // FIXME: Why do we assume `creation_url` is non-empty here? Is this a spec bug?
         // FIXME: Why do we assume `top_level_creation_url` is non-empty here? Is this a spec bug?
-        TRY(HTML::WindowEnvironmentSettingsObject::setup(
+        HTML::WindowEnvironmentSettingsObject::setup(
             creation_url.value(),
             move(realm_execution_context),
             navigation_params.reserved_environment,
             top_level_creation_url.value(),
-            top_level_origin));
+            top_level_origin);
     }
 
     // FIXME: 7. Let loadTimingInfo be a new document load timing info with its navigation start time set to response's timing info's start time.
@@ -252,7 +252,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Document>> Document::create_and_initialize(
     //    FIXME: and cross-origin opener policy is navigationParams's cross-origin opener policy,
     //    FIXME: load timing info is loadTimingInfo,
     //    and navigation id is navigationParams's id.
-    auto document = TRY(HTML::HTMLDocument::create(window->realm()));
+    auto document = HTML::HTMLDocument::create(window->realm());
     document->m_type = type;
     document->m_content_type = move(content_type);
     document->set_origin(navigation_params.origin);
@@ -310,9 +310,9 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Document>> Document::construct_impl(JS::Rea
     return Document::create(realm);
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Document>> Document::create(JS::Realm& realm, AK::URL const& url)
+JS::NonnullGCPtr<Document> Document::create(JS::Realm& realm, AK::URL const& url)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Document>(realm, realm, url));
+    return realm.heap().allocate<Document>(realm, realm, url);
 }
 
 Document::Document(JS::Realm& realm, const AK::URL& url)
@@ -341,7 +341,7 @@ void Document::initialize(JS::Realm& realm)
     Base::initialize(realm);
     set_prototype(&Bindings::ensure_web_prototype<Bindings::DocumentPrototype>(realm, "Document"));
 
-    m_selection = MUST(heap().allocate<Selection::Selection>(realm, realm, *this));
+    m_selection = heap().allocate<Selection::Selection>(realm, realm, *this);
 
     m_list_of_available_images = make<HTML::ListOfAvailableImages>();
 }
@@ -1162,7 +1162,7 @@ void Document::set_hovered_node(Node* node)
         // FIXME: Check if we need to dispatch these events in a specific order.
         for (auto target = old_hovered_node; target && target.ptr() != common_ancestor; target = target->parent()) {
             // FIXME: Populate the event with mouse coordinates, etc.
-            target->dispatch_event(UIEvents::MouseEvent::create(realm(), UIEvents::EventNames::mouseleave).release_value_but_fixme_should_propagate_errors());
+            target->dispatch_event(UIEvents::MouseEvent::create(realm(), UIEvents::EventNames::mouseleave));
         }
     }
 
@@ -1171,7 +1171,7 @@ void Document::set_hovered_node(Node* node)
         // FIXME: Check if we need to dispatch these events in a specific order.
         for (auto target = m_hovered_node; target && target.ptr() != common_ancestor; target = target->parent()) {
             // FIXME: Populate the event with mouse coordinates, etc.
-            target->dispatch_event(UIEvents::MouseEvent::create(realm(), UIEvents::EventNames::mouseenter).release_value_but_fixme_should_propagate_errors());
+            target->dispatch_event(UIEvents::MouseEvent::create(realm(), UIEvents::EventNames::mouseenter));
         }
     }
 }
@@ -1180,7 +1180,7 @@ JS::NonnullGCPtr<HTMLCollection> Document::get_elements_by_name(DeprecatedString
 {
     return HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [name](Element const& element) {
         return element.name() == name;
-    }).release_value_but_fixme_should_propagate_errors();
+    });
 }
 
 JS::NonnullGCPtr<HTMLCollection> Document::get_elements_by_class_name(DeprecatedFlyString const& class_names)
@@ -1195,14 +1195,14 @@ JS::NonnullGCPtr<HTMLCollection> Document::get_elements_by_class_name(Deprecated
                 return false;
         }
         return true;
-    }).release_value_but_fixme_should_propagate_errors();
+    });
 }
 
 // https://html.spec.whatwg.org/multipage/obsolete.html#dom-document-applets
 JS::NonnullGCPtr<HTMLCollection> Document::applets()
 {
     if (!m_applets)
-        m_applets = HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [](auto&) { return false; }).release_value_but_fixme_should_propagate_errors();
+        m_applets = HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [](auto&) { return false; });
     return *m_applets;
 }
 
@@ -1212,7 +1212,7 @@ JS::NonnullGCPtr<HTMLCollection> Document::anchors()
     if (!m_anchors) {
         m_anchors = HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [](Element const& element) {
             return is<HTML::HTMLAnchorElement>(element) && element.has_attribute(HTML::AttributeNames::name);
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_anchors;
 }
@@ -1223,7 +1223,7 @@ JS::NonnullGCPtr<HTMLCollection> Document::images()
     if (!m_images) {
         m_images = HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [](Element const& element) {
             return is<HTML::HTMLImageElement>(element);
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_images;
 }
@@ -1234,7 +1234,7 @@ JS::NonnullGCPtr<HTMLCollection> Document::embeds()
     if (!m_embeds) {
         m_embeds = HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [](Element const& element) {
             return is<HTML::HTMLEmbedElement>(element);
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_embeds;
 }
@@ -1251,7 +1251,7 @@ JS::NonnullGCPtr<HTMLCollection> Document::links()
     if (!m_links) {
         m_links = HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [](Element const& element) {
             return (is<HTML::HTMLAnchorElement>(element) || is<HTML::HTMLAreaElement>(element)) && element.has_attribute(HTML::AttributeNames::href);
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_links;
 }
@@ -1262,7 +1262,7 @@ JS::NonnullGCPtr<HTMLCollection> Document::forms()
     if (!m_forms) {
         m_forms = HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [](Element const& element) {
             return is<HTML::HTMLFormElement>(element);
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_forms;
 }
@@ -1273,7 +1273,7 @@ JS::NonnullGCPtr<HTMLCollection> Document::scripts()
     if (!m_scripts) {
         m_scripts = HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [](Element const& element) {
             return is<HTML::HTMLScriptElement>(element);
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_scripts;
 }
@@ -1284,7 +1284,7 @@ JS::NonnullGCPtr<HTMLCollection> Document::all()
     if (!m_all) {
         m_all = HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [](Element const&) {
             return true;
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_all;
 }
@@ -1417,17 +1417,17 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Element>> Document::create_element_ns(Depre
 
 JS::NonnullGCPtr<DocumentFragment> Document::create_document_fragment()
 {
-    return heap().allocate<DocumentFragment>(realm(), *this).release_allocated_value_but_fixme_should_propagate_errors();
+    return heap().allocate<DocumentFragment>(realm(), *this);
 }
 
 JS::NonnullGCPtr<Text> Document::create_text_node(DeprecatedString const& data)
 {
-    return heap().allocate<Text>(realm(), *this, data).release_allocated_value_but_fixme_should_propagate_errors();
+    return heap().allocate<Text>(realm(), *this, data);
 }
 
 JS::NonnullGCPtr<Comment> Document::create_comment(DeprecatedString const& data)
 {
-    return heap().allocate<Comment>(realm(), *this, data).release_allocated_value_but_fixme_should_propagate_errors();
+    return heap().allocate<Comment>(realm(), *this, data);
 }
 
 // https://dom.spec.whatwg.org/#dom-document-createprocessinginstruction
@@ -1438,12 +1438,12 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<ProcessingInstruction>> Document::create_pr
     // FIXME: 2. If data contains the string "?>", then throw an "InvalidCharacterError" DOMException.
 
     // 3. Return a new ProcessingInstruction node, with target set to target, data set to data, and node document set to this.
-    return MUST_OR_THROW_OOM(heap().allocate<ProcessingInstruction>(realm(), *this, data, target));
+    return heap().allocate<ProcessingInstruction>(realm(), *this, data, target);
 }
 
 JS::NonnullGCPtr<Range> Document::create_range()
 {
-    return Range::create(*this).release_value_but_fixme_should_propagate_errors();
+    return Range::create(*this);
 }
 
 // https://dom.spec.whatwg.org/#dom-document-createevent
@@ -1458,44 +1458,44 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Event>> Document::create_event(DeprecatedSt
     // 2. If interface is an ASCII case-insensitive match for any of the strings in the first column in the following table,
     //      then set constructor to the interface in the second column on the same row as the matching string:
     if (Infra::is_ascii_case_insensitive_match(interface, "beforeunloadevent"sv)) {
-        event = TRY(Event::create(realm, FlyString {})); // FIXME: Create BeforeUnloadEvent
+        event = Event::create(realm, FlyString {}); // FIXME: Create BeforeUnloadEvent
     } else if (Infra::is_ascii_case_insensitive_match(interface, "compositionevent"sv)) {
-        event = TRY(Event::create(realm, FlyString {})); // FIXME: Create CompositionEvent
+        event = Event::create(realm, FlyString {}); // FIXME: Create CompositionEvent
     } else if (Infra::is_ascii_case_insensitive_match(interface, "customevent"sv)) {
-        event = TRY(CustomEvent::create(realm, FlyString {}));
+        event = CustomEvent::create(realm, FlyString {});
     } else if (Infra::is_ascii_case_insensitive_match(interface, "devicemotionevent"sv)) {
-        event = TRY(Event::create(realm, FlyString {})); // FIXME: Create DeviceMotionEvent
+        event = Event::create(realm, FlyString {}); // FIXME: Create DeviceMotionEvent
     } else if (Infra::is_ascii_case_insensitive_match(interface, "deviceorientationevent"sv)) {
-        event = TRY(Event::create(realm, FlyString {})); // FIXME: Create DeviceOrientationEvent
+        event = Event::create(realm, FlyString {}); // FIXME: Create DeviceOrientationEvent
     } else if (Infra::is_ascii_case_insensitive_match(interface, "dragevent"sv)) {
-        event = TRY(Event::create(realm, FlyString {})); // FIXME: Create DragEvent
+        event = Event::create(realm, FlyString {}); // FIXME: Create DragEvent
     } else if (Infra::is_ascii_case_insensitive_match(interface, "event"sv)
         || Infra::is_ascii_case_insensitive_match(interface, "events"sv)) {
-        event = TRY(Event::create(realm, FlyString {}));
+        event = Event::create(realm, FlyString {});
     } else if (Infra::is_ascii_case_insensitive_match(interface, "focusevent"sv)) {
-        event = TRY(UIEvents::FocusEvent::create(realm, FlyString {}));
+        event = UIEvents::FocusEvent::create(realm, FlyString {});
     } else if (Infra::is_ascii_case_insensitive_match(interface, "hashchangeevent"sv)) {
-        event = TRY(Event::create(realm, FlyString {})); // FIXME: Create HashChangeEvent
+        event = Event::create(realm, FlyString {}); // FIXME: Create HashChangeEvent
     } else if (Infra::is_ascii_case_insensitive_match(interface, "htmlevents"sv)) {
-        event = TRY(Event::create(realm, FlyString {}));
+        event = Event::create(realm, FlyString {});
     } else if (Infra::is_ascii_case_insensitive_match(interface, "keyboardevent"sv)) {
-        event = TRY(UIEvents::KeyboardEvent::create(realm, String {}));
+        event = UIEvents::KeyboardEvent::create(realm, String {});
     } else if (Infra::is_ascii_case_insensitive_match(interface, "messageevent"sv)) {
-        event = TRY(HTML::MessageEvent::create(realm, String {}));
+        event = HTML::MessageEvent::create(realm, String {});
     } else if (Infra::is_ascii_case_insensitive_match(interface, "mouseevent"sv)
         || Infra::is_ascii_case_insensitive_match(interface, "mouseevents"sv)) {
-        event = TRY(UIEvents::MouseEvent::create(realm, FlyString {}));
+        event = UIEvents::MouseEvent::create(realm, FlyString {});
     } else if (Infra::is_ascii_case_insensitive_match(interface, "storageevent"sv)) {
-        event = TRY(Event::create(realm, FlyString {})); // FIXME: Create StorageEvent
+        event = Event::create(realm, FlyString {}); // FIXME: Create StorageEvent
     } else if (Infra::is_ascii_case_insensitive_match(interface, "svgevents"sv)) {
-        event = TRY(Event::create(realm, FlyString {}));
+        event = Event::create(realm, FlyString {});
     } else if (Infra::is_ascii_case_insensitive_match(interface, "textevent"sv)) {
-        event = TRY(Event::create(realm, FlyString {})); // FIXME: Create CompositionEvent
+        event = Event::create(realm, FlyString {}); // FIXME: Create CompositionEvent
     } else if (Infra::is_ascii_case_insensitive_match(interface, "touchevent"sv)) {
-        event = TRY(Event::create(realm, FlyString {})); // FIXME: Create TouchEvent
+        event = Event::create(realm, FlyString {}); // FIXME: Create TouchEvent
     } else if (Infra::is_ascii_case_insensitive_match(interface, "uievent"sv)
         || Infra::is_ascii_case_insensitive_match(interface, "uievents"sv)) {
-        event = TRY(UIEvents::UIEvent::create(realm, FlyString {}));
+        event = UIEvents::UIEvent::create(realm, FlyString {});
     }
 
     // 3. If constructor is null, then throw a "NotSupportedError" DOMException.
@@ -1896,7 +1896,7 @@ void Document::update_readiness(HTML::DocumentReadyState readiness_value)
     }
 
     // 4. Fire an event named readystatechange at document.
-    dispatch_event(Event::create(realm(), HTML::EventNames::readystatechange).release_value_but_fixme_should_propagate_errors());
+    dispatch_event(Event::create(realm(), HTML::EventNames::readystatechange));
 }
 
 Page* Document::page()
@@ -1948,7 +1948,7 @@ void Document::completely_finish_loading()
     // 5. Otherwise, if container is non-null, then queue an element task on the DOM manipulation task source given container to fire an event named load at container.
     else if (container) {
         container->queue_an_element_task(HTML::Task::Source::DOMManipulation, [container] {
-            container->dispatch_event(DOM::Event::create(container->realm(), HTML::EventNames::load).release_value_but_fixme_should_propagate_errors());
+            container->dispatch_event(DOM::Event::create(container->realm(), HTML::EventNames::load));
         });
     }
 
@@ -2037,7 +2037,7 @@ bool Document::is_active() const
 }
 
 // https://html.spec.whatwg.org/multipage/history.html#dom-document-location
-WebIDL::ExceptionOr<JS::GCPtr<HTML::Location>> Document::location()
+JS::GCPtr<HTML::Location> Document::location()
 {
     // The Document object's location attribute's getter must return this Document object's relevant global object's Location object,
     // if this Document object is fully active, and null otherwise.
@@ -2045,7 +2045,7 @@ WebIDL::ExceptionOr<JS::GCPtr<HTML::Location>> Document::location()
     if (!is_fully_active())
         return nullptr;
 
-    return TRY(window().location());
+    return window().location();
 }
 
 // https://html.spec.whatwg.org/multipage/interaction.html#dom-document-hidden
@@ -2084,7 +2084,7 @@ void Document::update_the_visibility_state(HTML::VisibilityState visibility_stat
     // FIXME: 3. Run any page visibility change steps which may be defined in other specifications, with visibility state and document.
 
     // 4. Fire an event named visibilitychange at document, with its bubbles attribute initialized to true.
-    auto event = DOM::Event::create(realm(), HTML::EventNames::visibilitychange).release_value_but_fixme_should_propagate_errors();
+    auto event = DOM::Event::create(realm(), HTML::EventNames::visibilitychange);
     event->set_bubbles(true);
     dispatch_event(event);
 }
@@ -2105,7 +2105,7 @@ void Document::run_the_resize_steps()
         return;
     m_last_viewport_size = viewport_size;
 
-    window().dispatch_event(DOM::Event::create(realm(), UIEvents::EventNames::resize).release_value_but_fixme_should_propagate_errors());
+    window().dispatch_event(DOM::Event::create(realm(), UIEvents::EventNames::resize));
 
     schedule_layout_update();
 }
@@ -2117,14 +2117,14 @@ void Document::run_the_scroll_steps()
     for (auto& target : m_pending_scroll_event_targets) {
         // 1. If target is a Document, fire an event named scroll that bubbles at target and fire an event named scroll at the VisualViewport that is associated with target.
         if (is<Document>(*target)) {
-            auto event = DOM::Event::create(realm(), HTML::EventNames::scroll).release_value_but_fixme_should_propagate_errors();
+            auto event = DOM::Event::create(realm(), HTML::EventNames::scroll);
             event->set_bubbles(true);
             target->dispatch_event(event);
             // FIXME: Fire at the associated VisualViewport
         }
         // 2. Otherwise, fire an event named scroll at target.
         else {
-            auto event = DOM::Event::create(realm(), HTML::EventNames::scroll).release_value_but_fixme_should_propagate_errors();
+            auto event = DOM::Event::create(realm(), HTML::EventNames::scroll);
             target->dispatch_event(event);
         }
     }
@@ -2164,7 +2164,7 @@ void Document::evaluate_media_queries_and_report_changes()
             CSS::MediaQueryListEventInit init;
             init.media = String::from_deprecated_string(media_query_list->media()).release_value_but_fixme_should_propagate_errors();
             init.matches = now_matches;
-            auto event = CSS::MediaQueryListEvent::create(realm(), HTML::EventNames::change, init).release_value_but_fixme_should_propagate_errors();
+            auto event = CSS::MediaQueryListEvent::create(realm(), HTML::EventNames::change, init);
             event->set_is_trusted(true);
             media_query_list->dispatch_event(*event);
         }
@@ -2191,7 +2191,7 @@ void Document::evaluate_media_rules()
 DOMImplementation* Document::implementation()
 {
     if (!m_implementation)
-        m_implementation = DOMImplementation::create(*this).release_value_but_fixme_should_propagate_errors();
+        m_implementation = DOMImplementation::create(*this);
     return m_implementation;
 }
 
@@ -2323,7 +2323,7 @@ JS::NonnullGCPtr<NodeIterator> Document::create_node_iterator(Node& root, unsign
 // https://dom.spec.whatwg.org/#dom-document-createtreewalker
 JS::NonnullGCPtr<TreeWalker> Document::create_tree_walker(Node& root, unsigned what_to_show, JS::GCPtr<NodeFilter> filter)
 {
-    return TreeWalker::create(root, what_to_show, filter).release_value_but_fixme_should_propagate_errors();
+    return TreeWalker::create(root, what_to_show, filter);
 }
 
 void Document::register_node_iterator(Badge<NodeIterator>, NodeIterator& node_iterator)
@@ -2386,7 +2386,7 @@ void Document::check_favicon_after_loading_link_resource()
             return false;
 
         return static_cast<HTML::HTMLLinkElement const&>(element).has_loaded_icon();
-    }).release_value_but_fixme_should_propagate_errors();
+    });
 
     if (favicon_link_elements->length() == 0) {
         dbgln_if(SPAM_DEBUG, "No favicon found to be used");
@@ -2437,7 +2437,7 @@ JS::GCPtr<HTML::CustomElementDefinition> Document::lookup_custom_element_definit
         return nullptr;
 
     // 3. Let registry be document's relevant global object's CustomElementRegistry object.
-    auto registry = window().custom_elements().release_value_but_fixme_should_propagate_errors();
+    auto registry = window().custom_elements();
 
     // 4. If there is custom element definition in registry with name and local name both equal to localName, return that custom element definition.
     auto converted_local_name = String::from_deprecated_string(local_name).release_value_but_fixme_should_propagate_errors();
@@ -2458,7 +2458,7 @@ JS::GCPtr<HTML::CustomElementDefinition> Document::lookup_custom_element_definit
 CSS::StyleSheetList& Document::style_sheets()
 {
     if (!m_style_sheets)
-        m_style_sheets = CSS::StyleSheetList::create(*this).release_value_but_fixme_should_propagate_errors();
+        m_style_sheets = CSS::StyleSheetList::create(*this);
     return *m_style_sheets;
 }
 
@@ -2470,7 +2470,7 @@ CSS::StyleSheetList const& Document::style_sheets() const
 JS::NonnullGCPtr<HTML::History> Document::history()
 {
     if (!m_history)
-        m_history = HTML::History::create(realm(), *this).release_value_but_fixme_should_propagate_errors();
+        m_history = HTML::History::create(realm(), *this);
     return *m_history;
 }
 
@@ -2747,7 +2747,7 @@ void Document::unload(bool recursive_flag, Optional<DocumentUnloadTimingInfo> un
         // then fire an event named unload at document's relevant global object, with legacy target override flag set.
         // FIXME: The legacy target override flag is currently set by a virtual override of dispatch_event()
         //        We should reorganize this so that the flag appears explicitly here instead.
-        auto event = DOM::Event::create(realm(), HTML::EventNames::unload).release_value_but_fixme_should_propagate_errors();
+        auto event = DOM::Event::create(realm(), HTML::EventNames::unload);
         global_object().dispatch_event(event);
     }
 
@@ -2860,7 +2860,7 @@ JS::NonnullGCPtr<DOM::Document> Document::appropriate_template_contents_owner_do
         // 1. If doc does not yet have an associated inert template document, then:
         if (!m_associated_inert_template_document) {
             // 1. Let new doc be a new Document (whose browsing context is null). This is "a Document created by this algorithm" for the purposes of the step above.
-            auto new_document = HTML::HTMLDocument::create(realm()).release_value_but_fixme_should_propagate_errors();
+            auto new_document = HTML::HTMLDocument::create(realm());
             new_document->m_created_for_appropriate_template_contents = true;
 
             // 2. If doc is an HTML document, mark new doc as an HTML document also.
@@ -2880,7 +2880,7 @@ JS::NonnullGCPtr<DOM::Document> Document::appropriate_template_contents_owner_do
 DeprecatedString Document::dump_accessibility_tree_as_json()
 {
     StringBuilder builder;
-    auto accessibility_tree = AccessibilityTreeNode::create(this, nullptr).release_value_but_fixme_should_propagate_errors();
+    auto accessibility_tree = AccessibilityTreeNode::create(this, nullptr);
     build_accessibility_tree(*&accessibility_tree);
     auto json = MUST(JsonObjectSerializer<>::try_create(builder));
 
@@ -2950,7 +2950,7 @@ HTML::ListOfAvailableImages const& Document::list_of_available_images() const
 JS::NonnullGCPtr<CSS::VisualViewport> Document::visual_viewport()
 {
     if (!m_visual_viewport)
-        m_visual_viewport = CSS::VisualViewport::create(*this).release_value_but_fixme_should_propagate_errors();
+        m_visual_viewport = CSS::VisualViewport::create(*this);
     return *m_visual_viewport;
 }
 
@@ -3025,7 +3025,7 @@ void Document::queue_an_intersection_observer_entry(IntersectionObserver::Inters
     auto& realm = this->realm();
 
     // 1. Construct an IntersectionObserverEntry, passing in time, rootBounds, boundingClientRect, intersectionRect, isIntersecting, and target.
-    auto entry = realm.heap().allocate<IntersectionObserver::IntersectionObserverEntry>(realm, realm, time, root_bounds, bounding_client_rect, intersection_rect, is_intersecting, intersection_ratio, target).release_allocated_value_but_fixme_should_propagate_errors();
+    auto entry = realm.heap().allocate<IntersectionObserver::IntersectionObserverEntry>(realm, realm, time, root_bounds, bounding_client_rect, intersection_rect, is_intersecting, intersection_ratio, target);
 
     // 2. Append it to observer’s internal [[QueuedEntries]] slot.
     observer.queue_entry({}, entry);
diff --git a/Userland/Libraries/LibWeb/DOM/Document.h b/Userland/Libraries/LibWeb/DOM/Document.h
index cac5a93d228..3addf25a265 100644
--- a/Userland/Libraries/LibWeb/DOM/Document.h
+++ b/Userland/Libraries/LibWeb/DOM/Document.h
@@ -91,7 +91,7 @@ public:
 
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<Document>> create_and_initialize(Type, DeprecatedString content_type, HTML::NavigationParams);
 
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Document>> create(JS::Realm&, AK::URL const& url = "about:blank"sv);
+    [[nodiscard]] static JS::NonnullGCPtr<Document> create(JS::Realm&, AK::URL const& url = "about:blank"sv);
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<Document>> construct_impl(JS::Realm&);
     virtual ~Document() override;
 
@@ -362,7 +362,7 @@ public:
     JS::NonnullGCPtr<HTML::History> history();
     JS::NonnullGCPtr<HTML::History> history() const;
 
-    WebIDL::ExceptionOr<JS::GCPtr<HTML::Location>> location();
+    [[nodiscard]] JS::GCPtr<HTML::Location> location();
 
     size_t number_of_things_delaying_the_load_event() { return m_number_of_things_delaying_the_load_event; }
     void increment_number_of_things_delaying_the_load_event(Badge<DocumentLoadEventDelayer>);
diff --git a/Userland/Libraries/LibWeb/DOM/DocumentFragment.cpp b/Userland/Libraries/LibWeb/DOM/DocumentFragment.cpp
index c9db3349048..297cbcca00a 100644
--- a/Userland/Libraries/LibWeb/DOM/DocumentFragment.cpp
+++ b/Userland/Libraries/LibWeb/DOM/DocumentFragment.cpp
@@ -35,7 +35,7 @@ void DocumentFragment::set_host(Web::DOM::Element* element)
 WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> DocumentFragment::construct_impl(JS::Realm& realm)
 {
     auto& window = verify_cast<HTML::Window>(realm.global_object());
-    return MUST_OR_THROW_OOM(realm.heap().allocate<DocumentFragment>(realm, window.associated_document()));
+    return realm.heap().allocate<DocumentFragment>(realm, window.associated_document());
 }
 
 }
diff --git a/Userland/Libraries/LibWeb/DOM/DocumentLoading.cpp b/Userland/Libraries/LibWeb/DOM/DocumentLoading.cpp
index 947d6bd76d7..bc90501ec3a 100644
--- a/Userland/Libraries/LibWeb/DOM/DocumentLoading.cpp
+++ b/Userland/Libraries/LibWeb/DOM/DocumentLoading.cpp
@@ -119,7 +119,7 @@ static bool build_image_document(DOM::Document& document, ByteBuffer const& data
     MUST(head_element->append_child(title_element));
 
     auto basename = LexicalPath::basename(document.url().serialize_path());
-    auto title_text = document.heap().allocate<DOM::Text>(document.realm(), document, DeprecatedString::formatted("{} [{}x{}]", basename, bitmap->width(), bitmap->height())).release_allocated_value_but_fixme_should_propagate_errors();
+    auto title_text = document.heap().allocate<DOM::Text>(document.realm(), document, DeprecatedString::formatted("{} [{}x{}]", basename, bitmap->width(), bitmap->height()));
     MUST(title_element->append_child(*title_text));
 
     auto body_element = DOM::create_element(document, HTML::TagNames::body, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
diff --git a/Userland/Libraries/LibWeb/DOM/DocumentType.cpp b/Userland/Libraries/LibWeb/DOM/DocumentType.cpp
index 4127bc5474f..567ff1eca05 100644
--- a/Userland/Libraries/LibWeb/DOM/DocumentType.cpp
+++ b/Userland/Libraries/LibWeb/DOM/DocumentType.cpp
@@ -9,9 +9,9 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentType>> DocumentType::create(Document& document)
+JS::NonnullGCPtr<DocumentType> DocumentType::create(Document& document)
 {
-    return MUST_OR_THROW_OOM(document.heap().allocate<DocumentType>(document.realm(), document));
+    return document.heap().allocate<DocumentType>(document.realm(), document);
 }
 
 DocumentType::DocumentType(Document& document)
diff --git a/Userland/Libraries/LibWeb/DOM/DocumentType.h b/Userland/Libraries/LibWeb/DOM/DocumentType.h
index 32c7afa2876..d16464d69e6 100644
--- a/Userland/Libraries/LibWeb/DOM/DocumentType.h
+++ b/Userland/Libraries/LibWeb/DOM/DocumentType.h
@@ -18,7 +18,7 @@ class DocumentType final
     WEB_PLATFORM_OBJECT(DocumentType, Node);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentType>> create(Document&);
+    [[nodiscard]] static JS::NonnullGCPtr<DocumentType> create(Document&);
 
     virtual ~DocumentType() override = default;
 
diff --git a/Userland/Libraries/LibWeb/DOM/Element.cpp b/Userland/Libraries/LibWeb/DOM/Element.cpp
index 4f3b11d1310..13b81e587b9 100644
--- a/Userland/Libraries/LibWeb/DOM/Element.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Element.cpp
@@ -75,7 +75,7 @@ void Element::initialize(JS::Realm& realm)
     Base::initialize(realm);
     set_prototype(&Bindings::ensure_web_prototype<Bindings::ElementPrototype>(realm, "Element"));
 
-    m_attributes = MUST(NamedNodeMap::create(*this));
+    m_attributes = NamedNodeMap::create(*this);
 }
 
 void Element::visit_edges(Cell::Visitor& visitor)
@@ -130,7 +130,7 @@ WebIDL::ExceptionOr<void> Element::set_attribute(DeprecatedFlyString const& name
 
     // 4. If attribute is null, create an attribute whose local name is qualifiedName, value is value, and node document is this’s node document, then append this attribute to this, and then return.
     if (!attribute) {
-        auto new_attribute = TRY(Attr::create(document(), insert_as_lowercase ? name.to_lowercase() : name, value));
+        auto new_attribute = Attr::create(document(), insert_as_lowercase ? name.to_lowercase() : name, value);
         m_attributes->append_attribute(new_attribute);
 
         attribute = new_attribute.ptr();
@@ -264,7 +264,7 @@ WebIDL::ExceptionOr<bool> Element::toggle_attribute(DeprecatedFlyString const& n
     if (!attribute) {
         // 1. If force is not given or is true, create an attribute whose local name is qualifiedName, value is the empty string, and node document is this’s node document, then append this attribute to this, and then return true.
         if (!force.has_value() || force.value()) {
-            auto new_attribute = TRY(Attr::create(document(), insert_as_lowercase ? name.to_lowercase() : name, ""));
+            auto new_attribute = Attr::create(document(), insert_as_lowercase ? name.to_lowercase() : name, "");
             m_attributes->append_attribute(new_attribute);
 
             attribute_changed(new_attribute->local_name(), "");
@@ -476,7 +476,7 @@ Element::RequiredInvalidationAfterStyleChange Element::recompute_style()
 
 NonnullRefPtr<CSS::StyleProperties> Element::resolved_css_values()
 {
-    auto element_computed_style = CSS::ResolvedCSSStyleDeclaration::create(*this).release_value_but_fixme_should_propagate_errors();
+    auto element_computed_style = CSS::ResolvedCSSStyleDeclaration::create(*this);
     auto properties = CSS::StyleProperties::create();
 
     for (auto i = to_underlying(CSS::first_property_id); i <= to_underlying(CSS::last_property_id); ++i) {
@@ -493,7 +493,7 @@ NonnullRefPtr<CSS::StyleProperties> Element::resolved_css_values()
 DOMTokenList* Element::class_list()
 {
     if (!m_class_list)
-        m_class_list = DOMTokenList::create(*this, HTML::AttributeNames::class_).release_value_but_fixme_should_propagate_errors();
+        m_class_list = DOMTokenList::create(*this, HTML::AttributeNames::class_);
     return m_class_list;
 }
 
@@ -528,7 +528,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<ShadowRoot>> Element::attach_shadow(ShadowR
         return WebIDL::NotSupportedError::create(realm(), "Element already is a shadow host");
 
     // 5. Let shadow be a new shadow root whose node document is this’s node document, host is this, and mode is init["mode"].
-    auto shadow = MUST_OR_THROW_OOM(heap().allocate<ShadowRoot>(realm(), document(), *this, init.mode));
+    auto shadow = heap().allocate<ShadowRoot>(realm(), document(), *this, init.mode);
 
     // 6. Set shadow’s delegates focus to init["delegatesFocus"].
     shadow->set_delegates_focus(init.delegates_focus);
@@ -651,7 +651,7 @@ JS::NonnullGCPtr<HTMLCollection> Element::get_elements_by_class_name(DeprecatedF
                 return false;
         }
         return true;
-    }).release_value_but_fixme_should_propagate_errors();
+    });
 }
 
 // https://dom.spec.whatwg.org/#element-shadow-host
@@ -676,7 +676,7 @@ void Element::set_shadow_root(JS::GCPtr<ShadowRoot> shadow_root)
 CSS::CSSStyleDeclaration* Element::style_for_bindings()
 {
     if (!m_inline_style)
-        m_inline_style = CSS::ElementInlineCSSStyleDeclaration::create(*this, {}, {}).release_value_but_fixme_should_propagate_errors();
+        m_inline_style = CSS::ElementInlineCSSStyleDeclaration::create(*this, {}, {});
     return m_inline_style;
 }
 
@@ -723,7 +723,7 @@ JS::NonnullGCPtr<Geometry::DOMRect> Element::get_bounding_client_rect() const
     VERIFY(document().browsing_context());
     auto viewport_offset = document().browsing_context()->viewport_scroll_offset();
 
-    return Geometry::DOMRect::create(realm(), paintable_box->absolute_rect().translated(-viewport_offset.x(), -viewport_offset.y()).to_type<float>()).release_value_but_fixme_should_propagate_errors();
+    return Geometry::DOMRect::create(realm(), paintable_box->absolute_rect().translated(-viewport_offset.x(), -viewport_offset.y()).to_type<float>());
 }
 
 // https://drafts.csswg.org/cssom-view/#dom-element-getclientrects
@@ -736,7 +736,7 @@ JS::NonnullGCPtr<Geometry::DOMRectList> Element::get_client_rects() const
 
     // 1. If the element on which it was invoked does not have an associated layout box return an empty DOMRectList object and stop this algorithm.
     if (!layout_node() || !layout_node()->is_box())
-        return Geometry::DOMRectList::create(realm(), move(rects)).release_value_but_fixme_should_propagate_errors();
+        return Geometry::DOMRectList::create(realm(), move(rects));
 
     // FIXME: 2. If the element has an associated SVG layout box return a DOMRectList object containing a single DOMRect object that describes
     // the bounding box of the element as defined by the SVG specification, applying the transforms that apply to the element and its ancestors.
@@ -750,7 +750,7 @@ JS::NonnullGCPtr<Geometry::DOMRectList> Element::get_client_rects() const
 
     auto bounding_rect = get_bounding_client_rect();
     rects.append(*bounding_rect);
-    return Geometry::DOMRectList::create(realm(), move(rects)).release_value_but_fixme_should_propagate_errors();
+    return Geometry::DOMRectList::create(realm(), move(rects));
 }
 
 int Element::client_top() const
@@ -1364,7 +1364,7 @@ WebIDL::ExceptionOr<JS::GCPtr<Element>> Element::insert_adjacent_element(Depreca
 WebIDL::ExceptionOr<void> Element::insert_adjacent_text(DeprecatedString const& where, DeprecatedString const& data)
 {
     // 1. Let text be a new Text node whose data is data and node document is this’s node document.
-    auto text = MUST_OR_THROW_OOM(heap().allocate<DOM::Text>(realm(), document(), data));
+    auto text = heap().allocate<DOM::Text>(realm(), document(), data);
 
     // 2. Run insert adjacent, given this, where, and text.
     // Spec Note: This method returns nothing because it existed before we had a chance to design it.
diff --git a/Userland/Libraries/LibWeb/DOM/ElementFactory.cpp b/Userland/Libraries/LibWeb/DOM/ElementFactory.cpp
index 017233f915c..1c2fad9521b 100644
--- a/Userland/Libraries/LibWeb/DOM/ElementFactory.cpp
+++ b/Userland/Libraries/LibWeb/DOM/ElementFactory.cpp
@@ -270,221 +270,221 @@ bool is_unknown_html_element(DeprecatedFlyString const& tag_name)
 }
 
 // https://html.spec.whatwg.org/#elements-in-the-dom:element-interface
-static WebIDL::ExceptionOr<JS::NonnullGCPtr<Element>> create_html_element(JS::Realm& realm, Document& document, QualifiedName qualified_name)
+static JS::NonnullGCPtr<Element> create_html_element(JS::Realm& realm, Document& document, QualifiedName qualified_name)
 {
     auto lowercase_tag_name = qualified_name.local_name().to_lowercase();
 
     if (lowercase_tag_name == HTML::TagNames::a)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLAnchorElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLAnchorElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::area)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLAreaElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLAreaElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::audio)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLAudioElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLAudioElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::base)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLBaseElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLBaseElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::blink)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLBlinkElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLBlinkElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::body)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLBodyElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLBodyElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::br)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLBRElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLBRElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::button)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLButtonElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLButtonElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::canvas)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLCanvasElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLCanvasElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::data)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLDataElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLDataElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::datalist)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLDataListElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLDataListElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::details)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLDetailsElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLDetailsElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::dialog)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLDialogElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLDialogElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::dir)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLDirectoryElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLDirectoryElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::div)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLDivElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLDivElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::dl)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLDListElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLDListElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::embed)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLEmbedElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLEmbedElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::fieldset)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLFieldSetElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLFieldSetElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::font)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLFontElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLFontElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::form)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLFormElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLFormElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::frame)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLFrameElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLFrameElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::frameset)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLFrameSetElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLFrameSetElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::head)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLHeadElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLHeadElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name.is_one_of(HTML::TagNames::h1, HTML::TagNames::h2, HTML::TagNames::h3, HTML::TagNames::h4, HTML::TagNames::h5, HTML::TagNames::h6))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLHeadingElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLHeadingElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::hr)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLHRElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLHRElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::html)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLHtmlElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLHtmlElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::iframe)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLIFrameElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLIFrameElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::img)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLImageElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLImageElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::input)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLInputElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLInputElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::label)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLLabelElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLLabelElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::legend)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLLegendElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLLegendElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::li)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLLIElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLLIElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::link)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLLinkElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLLinkElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::map)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLMapElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLMapElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::marquee)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLMarqueeElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLMarqueeElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::menu)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLMenuElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLMenuElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::meta)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLMetaElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLMetaElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::meter)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLMeterElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLMeterElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name.is_one_of(HTML::TagNames::ins, HTML::TagNames::del))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLModElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLModElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::object)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLObjectElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLObjectElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::ol)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLOListElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLOListElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::optgroup)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLOptGroupElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLOptGroupElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::option)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLOptionElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLOptionElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::output)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLOutputElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLOutputElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::p)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLParagraphElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLParagraphElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::param)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLParamElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLParamElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::picture)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLPictureElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLPictureElement>(realm, document, move(qualified_name));
     // NOTE: The obsolete elements "listing" and "xmp" are explicitly mapped to HTMLPreElement in the specification.
     if (lowercase_tag_name.is_one_of(HTML::TagNames::pre, HTML::TagNames::listing, HTML::TagNames::xmp))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLPreElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLPreElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::progress)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLProgressElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLProgressElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name.is_one_of(HTML::TagNames::blockquote, HTML::TagNames::q))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLQuoteElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLQuoteElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::script)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLScriptElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLScriptElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::select)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLSelectElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLSelectElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::slot)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLSlotElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLSlotElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::source)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLSourceElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLSourceElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::span)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLSpanElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLSpanElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::style)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLStyleElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLStyleElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::summary)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLSummaryElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLSummaryElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::caption)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLTableCaptionElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLTableCaptionElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name.is_one_of(Web::HTML::TagNames::td, Web::HTML::TagNames::th))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLTableCellElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLTableCellElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name.is_one_of(HTML::TagNames::colgroup, HTML::TagNames::col))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLTableColElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLTableColElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::table)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLTableElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLTableElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::tr)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLTableRowElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLTableRowElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name.is_one_of(HTML::TagNames::tbody, HTML::TagNames::thead, HTML::TagNames::tfoot))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLTableSectionElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLTableSectionElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::template_)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLTemplateElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLTemplateElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::textarea)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLTextAreaElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLTextAreaElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::time)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLTimeElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLTimeElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::title)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLTitleElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLTitleElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::track)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLTrackElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLTrackElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::ul)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLUListElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLUListElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name == HTML::TagNames::video)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLVideoElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLVideoElement>(realm, document, move(qualified_name));
     if (lowercase_tag_name.is_one_of(
             HTML::TagNames::article, HTML::TagNames::section, HTML::TagNames::nav, HTML::TagNames::aside, HTML::TagNames::hgroup, HTML::TagNames::header, HTML::TagNames::footer, HTML::TagNames::address, HTML::TagNames::dt, HTML::TagNames::dd, HTML::TagNames::figure, HTML::TagNames::figcaption, HTML::TagNames::main, HTML::TagNames::em, HTML::TagNames::strong, HTML::TagNames::small, HTML::TagNames::s, HTML::TagNames::cite, HTML::TagNames::dfn, HTML::TagNames::abbr, HTML::TagNames::ruby, HTML::TagNames::rt, HTML::TagNames::rp, HTML::TagNames::code, HTML::TagNames::var, HTML::TagNames::samp, HTML::TagNames::kbd, HTML::TagNames::sub, HTML::TagNames::sup, HTML::TagNames::i, HTML::TagNames::b, HTML::TagNames::u, HTML::TagNames::mark, HTML::TagNames::bdi, HTML::TagNames::bdo, HTML::TagNames::wbr, HTML::TagNames::noscript,
             // Obsolete
             HTML::TagNames::acronym, HTML::TagNames::basefont, HTML::TagNames::big, HTML::TagNames::center, HTML::TagNames::nobr, HTML::TagNames::noembed, HTML::TagNames::noframes, HTML::TagNames::plaintext, HTML::TagNames::rb, HTML::TagNames::rtc, HTML::TagNames::strike, HTML::TagNames::tt))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLElement>(realm, document, move(qualified_name));
     if (HTML::is_valid_custom_element_name(qualified_name.local_name()))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<HTML::HTMLElement>(realm, document, move(qualified_name));
 
-    return MUST_OR_THROW_OOM(realm.heap().allocate<HTML::HTMLUnknownElement>(realm, document, move(qualified_name)));
+    return realm.heap().allocate<HTML::HTMLUnknownElement>(realm, document, move(qualified_name));
 }
 
-static WebIDL::ExceptionOr<JS::GCPtr<SVG::SVGElement>> create_svg_element(JS::Realm& realm, Document& document, QualifiedName qualified_name)
+static JS::GCPtr<SVG::SVGElement> create_svg_element(JS::Realm& realm, Document& document, QualifiedName qualified_name)
 {
     auto const& local_name = qualified_name.local_name();
 
     if (local_name == SVG::TagNames::svg)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGSVGElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGSVGElement>(realm, document, move(qualified_name));
     // FIXME: Support SVG's mixedCase tag names properly.
     if (local_name.equals_ignoring_ascii_case(SVG::TagNames::clipPath))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGClipPathElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGClipPathElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::circle)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGCircleElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGCircleElement>(realm, document, move(qualified_name));
     if (local_name.equals_ignoring_ascii_case(SVG::TagNames::defs))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGDefsElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGDefsElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::ellipse)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGEllipseElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGEllipseElement>(realm, document, move(qualified_name));
     if (local_name.equals_ignoring_ascii_case(SVG::TagNames::foreignObject))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGForeignObjectElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGForeignObjectElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::line)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGLineElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGLineElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::linearGradient)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGLinearGradientElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGLinearGradientElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::mask)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGMaskElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGMaskElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::path)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGPathElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGPathElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::polygon)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGPolygonElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGPolygonElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::polyline)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGPolylineElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGPolylineElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::radialGradient)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGRadialGradientElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGRadialGradientElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::rect)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGRectElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGRectElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::g)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGGElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGGElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::stop)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGStopElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGStopElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::style)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGStyleElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGStyleElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::symbol)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGSymbolElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGSymbolElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::text)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGTextElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGTextElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::title)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGTitleElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGTitleElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::tspan)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGTSpanElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGTSpanElement>(realm, document, move(qualified_name));
     if (local_name == SVG::TagNames::use)
-        return MUST_OR_THROW_OOM(realm.heap().allocate<SVG::SVGUseElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<SVG::SVGUseElement>(realm, document, move(qualified_name));
 
     return nullptr;
 }
 
-static WebIDL::ExceptionOr<JS::GCPtr<MathML::MathMLElement>> create_mathml_element(JS::Realm& realm, Document& document, QualifiedName qualified_name)
+static JS::GCPtr<MathML::MathMLElement> create_mathml_element(JS::Realm& realm, Document& document, QualifiedName qualified_name)
 {
-    auto const& local_name = TRY_OR_THROW_OOM(realm.vm(), FlyString::from_deprecated_fly_string(qualified_name.local_name()));
+    auto const& local_name = MUST(FlyString::from_deprecated_fly_string(qualified_name.local_name()));
 
     if (local_name.is_one_of(MathML::TagNames::annotation, MathML::TagNames::annotation_xml, MathML::TagNames::maction, MathML::TagNames::math, MathML::TagNames::merror, MathML::TagNames::mfrac, MathML::TagNames::mi, MathML::TagNames::mmultiscripts, MathML::TagNames::mn, MathML::TagNames::mo, MathML::TagNames::mover, MathML::TagNames::mpadded, MathML::TagNames::mphantom, MathML::TagNames::mprescripts, MathML::TagNames::mroot, MathML::TagNames::mrow, MathML::TagNames::ms, MathML::TagNames::mspace, MathML::TagNames::msqrt, MathML::TagNames::mstyle, MathML::TagNames::msub, MathML::TagNames::msubsup, MathML::TagNames::msup, MathML::TagNames::mtable, MathML::TagNames::mtd, MathML::TagNames::mtext, MathML::TagNames::mtr, MathML::TagNames::munder, MathML::TagNames::munderover, MathML::TagNames::semantics))
-        return MUST_OR_THROW_OOM(realm.heap().allocate<MathML::MathMLElement>(realm, document, move(qualified_name)));
+        return realm.heap().allocate<MathML::MathMLElement>(realm, document, move(qualified_name));
 
     return nullptr;
 }
@@ -511,7 +511,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Element>> create_element(Document& document
         // 2. Set result to a new element that implements interface, with no attributes, namespace set to the HTML namespace,
         //    namespace prefix set to prefix, local name set to localName, custom element state set to "undefined", custom element definition set to null,
         //    is value set to is, and node document set to document.
-        auto element = TRY(create_html_element(realm, document, QualifiedName { local_name, prefix, Namespace::HTML }));
+        auto element = create_html_element(realm, document, QualifiedName { local_name, prefix, Namespace::HTML });
 
         // 3. If the synchronous custom elements flag is set, then run this step while catching any exceptions:
         if (synchronous_custom_elements_flag) {
@@ -596,7 +596,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Element>> create_element(Document& document
 
                 // 2. Set result to a new element that implements the HTMLUnknownElement interface, with no attributes, namespace set to the HTML namespace, namespace prefix set to prefix,
                 //    local name set to localName, custom element state set to "failed", custom element definition set to null, is value set to null, and node document set to document.
-                JS::NonnullGCPtr<Element> element = realm.heap().allocate<HTML::HTMLUnknownElement>(realm, document, QualifiedName { local_name, prefix, Namespace::HTML }).release_allocated_value_but_fixme_should_propagate_errors();
+                JS::NonnullGCPtr<Element> element = realm.heap().allocate<HTML::HTMLUnknownElement>(realm, document, QualifiedName { local_name, prefix, Namespace::HTML });
                 element->set_custom_element_state(CustomElementState::Failed);
                 return element;
             }
@@ -607,7 +607,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Element>> create_element(Document& document
         // 2. Otherwise:
         // 1. Set result to a new element that implements the HTMLElement interface, with no attributes, namespace set to the HTML namespace, namespace prefix set to prefix,
         //    local name set to localName, custom element state set to "undefined", custom element definition set to null, is value set to null, and node document set to document.
-        JS::NonnullGCPtr<Element> element = realm.heap().allocate<HTML::HTMLElement>(realm, document, QualifiedName { local_name, prefix, Namespace::HTML }).release_allocated_value_but_fixme_should_propagate_errors();
+        auto element = realm.heap().allocate<HTML::HTMLElement>(realm, document, QualifiedName { local_name, prefix, Namespace::HTML });
         element->set_custom_element_state(CustomElementState::Undefined);
 
         // 2. Enqueue a custom element upgrade reaction given result and definition.
@@ -624,7 +624,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Element>> create_element(Document& document
     auto qualified_name = QualifiedName { local_name, prefix, namespace_ };
 
     if (namespace_ == Namespace::HTML) {
-        auto element = TRY(create_html_element(realm, document, move(qualified_name)));
+        auto element = create_html_element(realm, document, move(qualified_name));
         element->set_is_value(move(is_value));
         element->set_custom_element_state(CustomElementState::Uncustomized);
 
@@ -637,7 +637,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Element>> create_element(Document& document
     }
 
     if (namespace_ == Namespace::SVG) {
-        auto element = TRY(create_svg_element(realm, document, qualified_name));
+        auto element = create_svg_element(realm, document, qualified_name);
         if (element) {
             element->set_is_value(move(is_value));
             element->set_custom_element_state(CustomElementState::Uncustomized);
@@ -646,7 +646,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Element>> create_element(Document& document
     }
 
     if (namespace_ == Namespace::MathML) {
-        auto element = TRY(create_mathml_element(realm, document, qualified_name));
+        auto element = create_mathml_element(realm, document, qualified_name);
         if (element) {
             element->set_is_value(move(is_value));
             element->set_custom_element_state(CustomElementState::Uncustomized);
@@ -660,7 +660,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Element>> create_element(Document& document
     // https://dom.spec.whatwg.org/#concept-element-interface
     // The element interface for any name and namespace is Element, unless stated otherwise.
     dbgln("Potential FIXME: Creating unknown generic element '{}' in namespace '{}'", local_name, namespace_);
-    JS::NonnullGCPtr<Element> element = realm.heap().allocate<DOM::Element>(realm, document, move(qualified_name)).release_allocated_value_but_fixme_should_propagate_errors();
+    auto element = realm.heap().allocate<DOM::Element>(realm, document, move(qualified_name));
     element->set_is_value(move(is_value));
     element->set_custom_element_state(CustomElementState::Uncustomized);
     return element;
diff --git a/Userland/Libraries/LibWeb/DOM/Event.cpp b/Userland/Libraries/LibWeb/DOM/Event.cpp
index 9031e06e67c..3998137470f 100644
--- a/Userland/Libraries/LibWeb/DOM/Event.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Event.cpp
@@ -14,9 +14,9 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Event>> Event::create(JS::Realm& realm, FlyString const& event_name, EventInit const& event_init)
+JS::NonnullGCPtr<Event> Event::create(JS::Realm& realm, FlyString const& event_name, EventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Event>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<Event>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<Event>> Event::construct_impl(JS::Realm& realm, FlyString const& event_name, EventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/DOM/Event.h b/Userland/Libraries/LibWeb/DOM/Event.h
index 53a158be2bc..b6645130bbe 100644
--- a/Userland/Libraries/LibWeb/DOM/Event.h
+++ b/Userland/Libraries/LibWeb/DOM/Event.h
@@ -45,7 +45,7 @@ public:
 
     using Path = Vector<PathEntry>;
 
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Event>> create(JS::Realm&, FlyString const& event_name, EventInit const& event_init = {});
+    [[nodiscard]] static JS::NonnullGCPtr<Event> create(JS::Realm&, FlyString const& event_name, EventInit const& event_init = {});
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<Event>> construct_impl(JS::Realm&, FlyString const& event_name, EventInit const& event_init);
 
     Event(JS::Realm&, FlyString const& type);
diff --git a/Userland/Libraries/LibWeb/DOM/EventTarget.cpp b/Userland/Libraries/LibWeb/DOM/EventTarget.cpp
index 98133b31354..f61efb6ccda 100644
--- a/Userland/Libraries/LibWeb/DOM/EventTarget.cpp
+++ b/Userland/Libraries/LibWeb/DOM/EventTarget.cpp
@@ -49,7 +49,7 @@ EventTarget::~EventTarget() = default;
 WebIDL::ExceptionOr<JS::NonnullGCPtr<EventTarget>> EventTarget::construct_impl(JS::Realm& realm)
 {
     // The new EventTarget() constructor steps are to do nothing.
-    return MUST_OR_THROW_OOM(realm.heap().allocate<EventTarget>(realm, realm));
+    return realm.heap().allocate<EventTarget>(realm, realm);
 }
 
 void EventTarget::initialize(JS::Realm& realm)
@@ -581,7 +581,7 @@ void EventTarget::activate_event_handler(FlyString const& name, HTML::EventHandl
     // 5. Let listener be a new event listener whose type is the event handler event type corresponding to eventHandler and callback is callback.
     auto listener = realm.heap().allocate_without_realm<DOMEventListener>();
     listener->type = name;
-    listener->callback = IDLEventListener::create(realm, *callback).release_value_but_fixme_should_propagate_errors();
+    listener->callback = IDLEventListener::create(realm, *callback);
 
     // 6. Add an event listener with eventTarget and listener.
     add_an_event_listener(*listener);
diff --git a/Userland/Libraries/LibWeb/DOM/HTMLCollection.cpp b/Userland/Libraries/LibWeb/DOM/HTMLCollection.cpp
index e76fca5c68e..9eb8d5dd7f8 100644
--- a/Userland/Libraries/LibWeb/DOM/HTMLCollection.cpp
+++ b/Userland/Libraries/LibWeb/DOM/HTMLCollection.cpp
@@ -13,9 +13,9 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<HTMLCollection>> HTMLCollection::create(ParentNode& root, Scope scope, Function<bool(Element const&)> filter)
+JS::NonnullGCPtr<HTMLCollection> HTMLCollection::create(ParentNode& root, Scope scope, Function<bool(Element const&)> filter)
 {
-    return MUST_OR_THROW_OOM(root.heap().allocate<HTMLCollection>(root.realm(), root, scope, move(filter)));
+    return root.heap().allocate<HTMLCollection>(root.realm(), root, scope, move(filter));
 }
 
 HTMLCollection::HTMLCollection(ParentNode& root, Scope scope, Function<bool(Element const&)> filter)
diff --git a/Userland/Libraries/LibWeb/DOM/HTMLCollection.h b/Userland/Libraries/LibWeb/DOM/HTMLCollection.h
index 3383980d7e6..49faad306f7 100644
--- a/Userland/Libraries/LibWeb/DOM/HTMLCollection.h
+++ b/Userland/Libraries/LibWeb/DOM/HTMLCollection.h
@@ -34,7 +34,7 @@ public:
         Children,
         Descendants,
     };
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<HTMLCollection>> create(ParentNode& root, Scope, Function<bool(Element const&)> filter);
+    [[nodiscard]] static JS::NonnullGCPtr<HTMLCollection> create(ParentNode& root, Scope, Function<bool(Element const&)> filter);
 
     virtual ~HTMLCollection() override;
 
diff --git a/Userland/Libraries/LibWeb/DOM/IDLEventListener.cpp b/Userland/Libraries/LibWeb/DOM/IDLEventListener.cpp
index 22e8a40d635..fadd6b49186 100644
--- a/Userland/Libraries/LibWeb/DOM/IDLEventListener.cpp
+++ b/Userland/Libraries/LibWeb/DOM/IDLEventListener.cpp
@@ -10,9 +10,9 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<IDLEventListener>> IDLEventListener::create(JS::Realm& realm, JS::NonnullGCPtr<WebIDL::CallbackType> callback)
+JS::NonnullGCPtr<IDLEventListener> IDLEventListener::create(JS::Realm& realm, JS::NonnullGCPtr<WebIDL::CallbackType> callback)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<IDLEventListener>(realm, realm, move(callback)));
+    return realm.heap().allocate<IDLEventListener>(realm, realm, move(callback));
 }
 
 IDLEventListener::IDLEventListener(JS::Realm& realm, JS::NonnullGCPtr<WebIDL::CallbackType> callback)
diff --git a/Userland/Libraries/LibWeb/DOM/IDLEventListener.h b/Userland/Libraries/LibWeb/DOM/IDLEventListener.h
index eadb1893ddf..672714babbb 100644
--- a/Userland/Libraries/LibWeb/DOM/IDLEventListener.h
+++ b/Userland/Libraries/LibWeb/DOM/IDLEventListener.h
@@ -28,7 +28,7 @@ class IDLEventListener final : public JS::Object {
     JS_OBJECT(IDLEventListener, JS::Object);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<IDLEventListener>> create(JS::Realm&, JS::NonnullGCPtr<WebIDL::CallbackType>);
+    [[nodiscard]] static JS::NonnullGCPtr<IDLEventListener> create(JS::Realm&, JS::NonnullGCPtr<WebIDL::CallbackType>);
     IDLEventListener(JS::Realm&, JS::NonnullGCPtr<WebIDL::CallbackType>);
 
     virtual ~IDLEventListener() = default;
diff --git a/Userland/Libraries/LibWeb/DOM/LiveNodeList.cpp b/Userland/Libraries/LibWeb/DOM/LiveNodeList.cpp
index cf12fe9c1f8..e3743ff4541 100644
--- a/Userland/Libraries/LibWeb/DOM/LiveNodeList.cpp
+++ b/Userland/Libraries/LibWeb/DOM/LiveNodeList.cpp
@@ -12,9 +12,9 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<NodeList>> LiveNodeList::create(JS::Realm& realm, Node& root, Scope scope, Function<bool(Node const&)> filter)
+JS::NonnullGCPtr<NodeList> LiveNodeList::create(JS::Realm& realm, Node& root, Scope scope, Function<bool(Node const&)> filter)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<LiveNodeList>(realm, realm, root, scope, move(filter)));
+    return realm.heap().allocate<LiveNodeList>(realm, realm, root, scope, move(filter));
 }
 
 LiveNodeList::LiveNodeList(JS::Realm& realm, Node& root, Scope scope, Function<bool(Node const&)> filter)
diff --git a/Userland/Libraries/LibWeb/DOM/LiveNodeList.h b/Userland/Libraries/LibWeb/DOM/LiveNodeList.h
index f9d527519a6..cffd68aafa4 100644
--- a/Userland/Libraries/LibWeb/DOM/LiveNodeList.h
+++ b/Userland/Libraries/LibWeb/DOM/LiveNodeList.h
@@ -23,7 +23,7 @@ public:
         Descendants,
     };
 
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<NodeList>> create(JS::Realm&, Node& root, Scope, Function<bool(Node const&)> filter);
+    [[nodiscard]] static JS::NonnullGCPtr<NodeList> create(JS::Realm&, Node& root, Scope, Function<bool(Node const&)> filter);
     virtual ~LiveNodeList() override;
 
     virtual u32 length() const override;
diff --git a/Userland/Libraries/LibWeb/DOM/MutationObserver.cpp b/Userland/Libraries/LibWeb/DOM/MutationObserver.cpp
index 9b877ff2064..8c42f3fb2d1 100644
--- a/Userland/Libraries/LibWeb/DOM/MutationObserver.cpp
+++ b/Userland/Libraries/LibWeb/DOM/MutationObserver.cpp
@@ -13,7 +13,7 @@ namespace Web::DOM {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<MutationObserver>> MutationObserver::construct_impl(JS::Realm& realm, JS::GCPtr<WebIDL::CallbackType> callback)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<MutationObserver>(realm, realm, callback));
+    return realm.heap().allocate<MutationObserver>(realm, realm, callback);
 }
 
 // https://dom.spec.whatwg.org/#dom-mutationobserver-mutationobserver
diff --git a/Userland/Libraries/LibWeb/DOM/MutationRecord.cpp b/Userland/Libraries/LibWeb/DOM/MutationRecord.cpp
index cd74d8e2a1c..8a1af51767b 100644
--- a/Userland/Libraries/LibWeb/DOM/MutationRecord.cpp
+++ b/Userland/Libraries/LibWeb/DOM/MutationRecord.cpp
@@ -12,9 +12,9 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<MutationRecord>> MutationRecord::create(JS::Realm& realm, FlyString const& type, Node const& target, NodeList& added_nodes, NodeList& removed_nodes, Node* previous_sibling, Node* next_sibling, DeprecatedString const& attribute_name, DeprecatedString const& attribute_namespace, DeprecatedString const& old_value)
+JS::NonnullGCPtr<MutationRecord> MutationRecord::create(JS::Realm& realm, FlyString const& type, Node const& target, NodeList& added_nodes, NodeList& removed_nodes, Node* previous_sibling, Node* next_sibling, DeprecatedString const& attribute_name, DeprecatedString const& attribute_namespace, DeprecatedString const& old_value)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<MutationRecord>(realm, realm, type, target, added_nodes, removed_nodes, previous_sibling, next_sibling, attribute_name, attribute_namespace, old_value));
+    return realm.heap().allocate<MutationRecord>(realm, realm, type, target, added_nodes, removed_nodes, previous_sibling, next_sibling, attribute_name, attribute_namespace, old_value);
 }
 
 MutationRecord::MutationRecord(JS::Realm& realm, FlyString const& type, Node const& target, NodeList& added_nodes, NodeList& removed_nodes, Node* previous_sibling, Node* next_sibling, DeprecatedString const& attribute_name, DeprecatedString const& attribute_namespace, DeprecatedString const& old_value)
diff --git a/Userland/Libraries/LibWeb/DOM/MutationRecord.h b/Userland/Libraries/LibWeb/DOM/MutationRecord.h
index bb2f16d94f0..690103d3cfa 100644
--- a/Userland/Libraries/LibWeb/DOM/MutationRecord.h
+++ b/Userland/Libraries/LibWeb/DOM/MutationRecord.h
@@ -16,7 +16,7 @@ class MutationRecord : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(MutationRecord, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<MutationRecord>> create(JS::Realm&, FlyString const& type, Node const& target, NodeList& added_nodes, NodeList& removed_nodes, Node* previous_sibling, Node* next_sibling, DeprecatedString const& attribute_name, DeprecatedString const& attribute_namespace, DeprecatedString const& old_value);
+    [[nodiscard]] static JS::NonnullGCPtr<MutationRecord> create(JS::Realm&, FlyString const& type, Node const& target, NodeList& added_nodes, NodeList& removed_nodes, Node* previous_sibling, Node* next_sibling, DeprecatedString const& attribute_name, DeprecatedString const& attribute_namespace, DeprecatedString const& old_value);
 
     virtual ~MutationRecord() override;
 
diff --git a/Userland/Libraries/LibWeb/DOM/NamedNodeMap.cpp b/Userland/Libraries/LibWeb/DOM/NamedNodeMap.cpp
index 044e72150fd..c168a2aeb56 100644
--- a/Userland/Libraries/LibWeb/DOM/NamedNodeMap.cpp
+++ b/Userland/Libraries/LibWeb/DOM/NamedNodeMap.cpp
@@ -13,10 +13,10 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<NamedNodeMap>> NamedNodeMap::create(Element& element)
+JS::NonnullGCPtr<NamedNodeMap> NamedNodeMap::create(Element& element)
 {
     auto& realm = element.realm();
-    return MUST_OR_THROW_OOM(realm.heap().allocate<NamedNodeMap>(realm, element));
+    return realm.heap().allocate<NamedNodeMap>(realm, element);
 }
 
 NamedNodeMap::NamedNodeMap(Element& element)
diff --git a/Userland/Libraries/LibWeb/DOM/NamedNodeMap.h b/Userland/Libraries/LibWeb/DOM/NamedNodeMap.h
index 09d283c0eb6..7a7e46d21e2 100644
--- a/Userland/Libraries/LibWeb/DOM/NamedNodeMap.h
+++ b/Userland/Libraries/LibWeb/DOM/NamedNodeMap.h
@@ -22,7 +22,7 @@ class NamedNodeMap : public Bindings::LegacyPlatformObject {
     WEB_PLATFORM_OBJECT(NamedNodeMap, Bindings::LegacyPlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<NamedNodeMap>> create(Element&);
+    [[nodiscard]] static JS::NonnullGCPtr<NamedNodeMap> create(Element&);
     ~NamedNodeMap() = default;
 
     virtual bool is_supported_property_index(u32 index) const override;
diff --git a/Userland/Libraries/LibWeb/DOM/Node.cpp b/Userland/Libraries/LibWeb/DOM/Node.cpp
index ba73680a6f5..66ef92be485 100644
--- a/Userland/Libraries/LibWeb/DOM/Node.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Node.cpp
@@ -777,7 +777,7 @@ JS::NonnullGCPtr<Node> Node::clone_node(Document* document, bool clone_children)
     else if (is<Document>(this)) {
         // Document
         auto document_ = verify_cast<Document>(this);
-        auto document_copy = Document::create(this->realm(), document_->url()).release_value_but_fixme_should_propagate_errors();
+        auto document_copy = Document::create(this->realm(), document_->url());
 
         // Set copy’s encoding, content type, URL, origin, type, and mode to those of node.
         document_copy->set_encoding(document_->encoding());
@@ -790,7 +790,7 @@ JS::NonnullGCPtr<Node> Node::clone_node(Document* document, bool clone_children)
     } else if (is<DocumentType>(this)) {
         // DocumentType
         auto document_type = verify_cast<DocumentType>(this);
-        auto document_type_copy = heap().allocate<DocumentType>(realm(), *document).release_allocated_value_but_fixme_should_propagate_errors();
+        auto document_type_copy = heap().allocate<DocumentType>(realm(), *document);
 
         // Set copy’s name, public ID, and system ID to those of node.
         document_type_copy->set_name(document_type->name());
@@ -807,26 +807,26 @@ JS::NonnullGCPtr<Node> Node::clone_node(Document* document, bool clone_children)
         auto text = verify_cast<Text>(this);
 
         // Set copy’s data to that of node.
-        auto text_copy = heap().allocate<Text>(realm(), *document, text->data()).release_allocated_value_but_fixme_should_propagate_errors();
+        auto text_copy = heap().allocate<Text>(realm(), *document, text->data());
         copy = move(text_copy);
     } else if (is<Comment>(this)) {
         // Comment
         auto comment = verify_cast<Comment>(this);
 
         // Set copy’s data to that of node.
-        auto comment_copy = heap().allocate<Comment>(realm(), *document, comment->data()).release_allocated_value_but_fixme_should_propagate_errors();
+        auto comment_copy = heap().allocate<Comment>(realm(), *document, comment->data());
         copy = move(comment_copy);
     } else if (is<ProcessingInstruction>(this)) {
         // ProcessingInstruction
         auto processing_instruction = verify_cast<ProcessingInstruction>(this);
 
         // Set copy’s target and data to those of node.
-        auto processing_instruction_copy = heap().allocate<ProcessingInstruction>(realm(), *document, processing_instruction->data(), processing_instruction->target()).release_allocated_value_but_fixme_should_propagate_errors();
+        auto processing_instruction_copy = heap().allocate<ProcessingInstruction>(realm(), *document, processing_instruction->data(), processing_instruction->target());
         copy = processing_instruction_copy;
     }
     // Otherwise, Do nothing.
     else if (is<DocumentFragment>(this)) {
-        copy = heap().allocate<DocumentFragment>(realm(), *document).release_allocated_value_but_fixme_should_propagate_errors();
+        copy = heap().allocate<DocumentFragment>(realm(), *document);
     }
 
     // FIXME: 4. Set copy’s node document and document to copy, if copy is a document, and set copy’s node document to document otherwise.
@@ -937,7 +937,7 @@ JS::NonnullGCPtr<NodeList> Node::child_nodes()
     if (!m_child_nodes) {
         m_child_nodes = LiveNodeList::create(realm(), *this, LiveNodeList::Scope::Children, [](auto&) {
             return true;
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_child_nodes;
 }
@@ -1259,7 +1259,7 @@ void Node::string_replace_all(DeprecatedString const& string)
 
     // 2. If string is not the empty string, then set node to a new Text node whose data is string and node document is parent’s node document.
     if (!string.is_empty())
-        node = heap().allocate<Text>(realm(), document(), string).release_allocated_value_but_fixme_should_propagate_errors();
+        node = heap().allocate<Text>(realm(), document(), string);
 
     // 3. Replace all with node within parent.
     replace_all(node);
@@ -1517,14 +1517,14 @@ void Node::queue_mutation_record(FlyString const& type, DeprecatedString attribu
     if (interested_observers.is_empty())
         return;
 
-    auto added_nodes_list = StaticNodeList::create(realm(), move(added_nodes)).release_value_but_fixme_should_propagate_errors();
-    auto removed_nodes_list = StaticNodeList::create(realm(), move(removed_nodes)).release_value_but_fixme_should_propagate_errors();
+    auto added_nodes_list = StaticNodeList::create(realm(), move(added_nodes));
+    auto removed_nodes_list = StaticNodeList::create(realm(), move(removed_nodes));
 
     // 4. For each observer → mappedOldValue of interestedObservers:
     for (auto& interested_observer : interested_observers) {
         // 1. Let record be a new MutationRecord object with its type set to type, target set to target, attributeName set to name, attributeNamespace set to namespace, oldValue set to mappedOldValue,
         //    addedNodes set to addedNodes, removedNodes set to removedNodes, previousSibling set to previousSibling, and nextSibling set to nextSibling.
-        auto record = MutationRecord::create(realm(), type, *this, added_nodes_list, removed_nodes_list, previous_sibling, next_sibling, attribute_name, attribute_namespace, /* mappedOldValue */ interested_observer.value).release_value_but_fixme_should_propagate_errors();
+        auto record = MutationRecord::create(realm(), type, *this, added_nodes_list, removed_nodes_list, previous_sibling, next_sibling, attribute_name, attribute_namespace, /* mappedOldValue */ interested_observer.value);
 
         // 2. Enqueue record to observer’s record queue.
         interested_observer.key->enqueue_record({}, move(record));
@@ -1661,7 +1661,7 @@ void Node::build_accessibility_tree(AccessibilityTreeNode& parent)
             return;
 
         if (element->include_in_accessibility_tree()) {
-            auto current_node = AccessibilityTreeNode::create(&document(), this).release_value_but_fixme_should_propagate_errors();
+            auto current_node = AccessibilityTreeNode::create(&document(), this);
             parent.append_child(current_node);
             if (has_child_nodes()) {
                 for_each_child([&current_node](DOM::Node& child) {
@@ -1674,7 +1674,7 @@ void Node::build_accessibility_tree(AccessibilityTreeNode& parent)
             });
         }
     } else if (is_text()) {
-        parent.append_child(AccessibilityTreeNode::create(&document(), this).release_value_but_fixme_should_propagate_errors());
+        parent.append_child(AccessibilityTreeNode::create(&document(), this));
         if (has_child_nodes()) {
             for_each_child([&parent](DOM::Node& child) {
                 child.build_accessibility_tree(parent);
diff --git a/Userland/Libraries/LibWeb/DOM/NodeFilter.cpp b/Userland/Libraries/LibWeb/DOM/NodeFilter.cpp
index 8342de9dc87..accc89fc19d 100644
--- a/Userland/Libraries/LibWeb/DOM/NodeFilter.cpp
+++ b/Userland/Libraries/LibWeb/DOM/NodeFilter.cpp
@@ -10,9 +10,9 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<NodeFilter>> NodeFilter::create(JS::Realm& realm, WebIDL::CallbackType& callback)
+JS::NonnullGCPtr<NodeFilter> NodeFilter::create(JS::Realm& realm, WebIDL::CallbackType& callback)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<NodeFilter>(realm, realm, callback));
+    return realm.heap().allocate<NodeFilter>(realm, realm, callback);
 }
 
 NodeFilter::NodeFilter(JS::Realm& realm, WebIDL::CallbackType& callback)
diff --git a/Userland/Libraries/LibWeb/DOM/NodeFilter.h b/Userland/Libraries/LibWeb/DOM/NodeFilter.h
index aa6cb55156b..387c01cbe1f 100644
--- a/Userland/Libraries/LibWeb/DOM/NodeFilter.h
+++ b/Userland/Libraries/LibWeb/DOM/NodeFilter.h
@@ -15,7 +15,7 @@ class NodeFilter final : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(NodeFilter, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<NodeFilter>> create(JS::Realm&, WebIDL::CallbackType&);
+    [[nodiscard]] static JS::NonnullGCPtr<NodeFilter> create(JS::Realm&, WebIDL::CallbackType&);
 
     virtual ~NodeFilter() = default;
 
diff --git a/Userland/Libraries/LibWeb/DOM/NodeIterator.cpp b/Userland/Libraries/LibWeb/DOM/NodeIterator.cpp
index bb9caf2cb9c..e61576c7717 100644
--- a/Userland/Libraries/LibWeb/DOM/NodeIterator.cpp
+++ b/Userland/Libraries/LibWeb/DOM/NodeIterator.cpp
@@ -51,7 +51,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<NodeIterator>> NodeIterator::create(Node& r
     // 2. Set iterator’s root and iterator’s reference to root.
     // 3. Set iterator’s pointer before reference to true.
     auto& realm = root.realm();
-    auto iterator = MUST_OR_THROW_OOM(realm.heap().allocate<NodeIterator>(realm, root));
+    auto iterator = realm.heap().allocate<NodeIterator>(realm, root);
 
     // 4. Set iterator’s whatToShow to whatToShow.
     iterator->m_what_to_show = what_to_show;
diff --git a/Userland/Libraries/LibWeb/DOM/NodeOperations.cpp b/Userland/Libraries/LibWeb/DOM/NodeOperations.cpp
index 91649fc8b26..1ebd908e0b7 100644
--- a/Userland/Libraries/LibWeb/DOM/NodeOperations.cpp
+++ b/Userland/Libraries/LibWeb/DOM/NodeOperations.cpp
@@ -22,19 +22,19 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Node>> convert_nodes_to_single_node(Vector<
     // 4. Otherwise, set node to a new DocumentFragment node whose node document is document, and then append each node in nodes, if any, to it.
     // 5. Return node.
 
-    auto potentially_convert_string_to_text_node = [&document](Variant<JS::Handle<Node>, DeprecatedString> const& node) -> JS::ThrowCompletionOr<JS::NonnullGCPtr<Node>> {
+    auto potentially_convert_string_to_text_node = [&document](Variant<JS::Handle<Node>, DeprecatedString> const& node) -> JS::NonnullGCPtr<Node> {
         if (node.has<JS::Handle<Node>>())
             return *node.get<JS::Handle<Node>>();
 
-        return MUST_OR_THROW_OOM(document.heap().allocate<DOM::Text>(document.realm(), document, node.get<DeprecatedString>()));
+        return document.heap().allocate<DOM::Text>(document.realm(), document, node.get<DeprecatedString>());
     };
 
     if (nodes.size() == 1)
-        return TRY(potentially_convert_string_to_text_node(nodes.first()));
+        return potentially_convert_string_to_text_node(nodes.first());
 
-    auto document_fragment = MUST_OR_THROW_OOM(document.heap().allocate<DOM::DocumentFragment>(document.realm(), document));
+    auto document_fragment = document.heap().allocate<DOM::DocumentFragment>(document.realm(), document);
     for (auto& unconverted_node : nodes) {
-        auto node = TRY(potentially_convert_string_to_text_node(unconverted_node));
+        auto node = potentially_convert_string_to_text_node(unconverted_node);
         (void)TRY(document_fragment->append_child(node));
     }
 
diff --git a/Userland/Libraries/LibWeb/DOM/ParentNode.cpp b/Userland/Libraries/LibWeb/DOM/ParentNode.cpp
index ff9acd99363..db38f3af5de 100644
--- a/Userland/Libraries/LibWeb/DOM/ParentNode.cpp
+++ b/Userland/Libraries/LibWeb/DOM/ParentNode.cpp
@@ -115,7 +115,7 @@ JS::NonnullGCPtr<HTMLCollection> ParentNode::children()
     if (!m_children) {
         m_children = HTMLCollection::create(*this, HTMLCollection::Scope::Children, [](Element const&) {
             return true;
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_children;
 }
@@ -128,7 +128,7 @@ JS::NonnullGCPtr<HTMLCollection> ParentNode::get_elements_by_tag_name(Deprecated
     if (qualified_name == "*") {
         return HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [](Element const&) {
             return true;
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
 
     // 2. Otherwise, if root’s node document is an HTML document, return a HTMLCollection rooted at root, whose filter matches the following descendant elements:
@@ -140,13 +140,13 @@ JS::NonnullGCPtr<HTMLCollection> ParentNode::get_elements_by_tag_name(Deprecated
 
             // - Whose namespace is not the HTML namespace and whose qualified name is qualifiedName.
             return element.qualified_name() == qualified_name;
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
 
     // 3. Otherwise, return a HTMLCollection rooted at root, whose filter matches descendant elements whose qualified name is qualifiedName.
     return HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [qualified_name](Element const& element) {
         return element.qualified_name() == qualified_name;
-    }).release_value_but_fixme_should_propagate_errors();
+    });
 }
 
 // https://dom.spec.whatwg.org/#concept-getelementsbytagnamens
@@ -162,27 +162,27 @@ JS::NonnullGCPtr<HTMLCollection> ParentNode::get_elements_by_tag_name_ns(Depreca
     if (namespace_ == "*" && local_name == "*") {
         return HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [](Element const&) {
             return true;
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
 
     // 3. Otherwise, if namespace is "*" (U+002A), return a HTMLCollection rooted at root, whose filter matches descendant elements whose local name is localName.
     if (namespace_ == "*") {
         return HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [local_name](Element const& element) {
             return element.local_name() == local_name;
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
 
     // 4. Otherwise, if localName is "*" (U+002A), return a HTMLCollection rooted at root, whose filter matches descendant elements whose namespace is namespace.
     if (local_name == "*") {
         return HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [namespace_](Element const& element) {
             return element.namespace_() == namespace_;
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
 
     // 5. Otherwise, return a HTMLCollection rooted at root, whose filter matches descendant elements whose namespace is namespace and local name is localName.
     return HTMLCollection::create(*this, HTMLCollection::Scope::Descendants, [namespace_, local_name](Element const& element) {
         return element.namespace_() == namespace_ && element.local_name() == local_name;
-    }).release_value_but_fixme_should_propagate_errors();
+    });
 }
 
 // https://dom.spec.whatwg.org/#dom-parentnode-prepend
diff --git a/Userland/Libraries/LibWeb/DOM/Range.cpp b/Userland/Libraries/LibWeb/DOM/Range.cpp
index dd0dc115d5e..49c62ab92ab 100644
--- a/Userland/Libraries/LibWeb/DOM/Range.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Range.cpp
@@ -31,21 +31,21 @@ HashTable<Range*>& Range::live_ranges()
     return ranges;
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Range>> Range::create(HTML::Window& window)
+JS::NonnullGCPtr<Range> Range::create(HTML::Window& window)
 {
     return Range::create(window.associated_document());
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Range>> Range::create(Document& document)
+JS::NonnullGCPtr<Range> Range::create(Document& document)
 {
     auto& realm = document.realm();
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Range>(realm, document));
+    return realm.heap().allocate<Range>(realm, document);
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Range>> Range::create(Node& start_container, u32 start_offset, Node& end_container, u32 end_offset)
+JS::NonnullGCPtr<Range> Range::create(Node& start_container, u32 start_offset, Node& end_container, u32 end_offset)
 {
     auto& realm = start_container.realm();
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Range>(realm, start_container, start_offset, end_container, end_offset));
+    return realm.heap().allocate<Range>(realm, start_container, start_offset, end_container, end_offset);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<Range>> Range::construct_impl(JS::Realm& realm)
@@ -430,12 +430,12 @@ WebIDL::ExceptionOr<void> Range::select_node_contents(Node& node)
 
 JS::NonnullGCPtr<Range> Range::clone_range() const
 {
-    return heap().allocate<Range>(shape().realm(), const_cast<Node&>(*m_start_container), m_start_offset, const_cast<Node&>(*m_end_container), m_end_offset).release_allocated_value_but_fixme_should_propagate_errors();
+    return heap().allocate<Range>(shape().realm(), const_cast<Node&>(*m_start_container), m_start_offset, const_cast<Node&>(*m_end_container), m_end_offset);
 }
 
 JS::NonnullGCPtr<Range> Range::inverted() const
 {
-    return heap().allocate<Range>(shape().realm(), const_cast<Node&>(*m_end_container), m_end_offset, const_cast<Node&>(*m_start_container), m_start_offset).release_allocated_value_but_fixme_should_propagate_errors();
+    return heap().allocate<Range>(shape().realm(), const_cast<Node&>(*m_end_container), m_end_offset, const_cast<Node&>(*m_start_container), m_start_offset);
 }
 
 JS::NonnullGCPtr<Range> Range::normalized() const
@@ -589,7 +589,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> Range::extract_contents(
 WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> Range::extract()
 {
     // 1. Let fragment be a new DocumentFragment node whose node document is range’s start node’s node document.
-    auto fragment = MUST_OR_THROW_OOM(heap().allocate<DOM::DocumentFragment>(realm(), const_cast<Document&>(start_container()->document())));
+    auto fragment = heap().allocate<DOM::DocumentFragment>(realm(), const_cast<Document&>(start_container()->document()));
 
     // 2. If range is collapsed, then return fragment.
     if (collapsed())
@@ -717,7 +717,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> Range::extract()
         TRY(fragment->append_child(clone));
 
         // 3. Let subrange be a new live range whose start is (original start node, original start offset) and whose end is (first partially contained child, first partially contained child’s length).
-        auto subrange = TRY(Range::create(original_start_node, original_start_offset, *first_partially_contained_child, first_partially_contained_child->length()));
+        auto subrange = Range::create(original_start_node, original_start_offset, *first_partially_contained_child, first_partially_contained_child->length());
 
         // 4. Let subfragment be the result of extracting subrange.
         auto subfragment = TRY(subrange->extract());
@@ -755,7 +755,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> Range::extract()
         TRY(fragment->append_child(clone));
 
         // 3. Let subrange be a new live range whose start is (last partially contained child, 0) and whose end is (original end node, original end offset).
-        auto subrange = TRY(Range::create(*last_partially_contained_child, 0, original_end_node, original_end_offset));
+        auto subrange = Range::create(*last_partially_contained_child, 0, original_end_node, original_end_offset);
 
         // 4. Let subfragment be the result of extracting subrange.
         auto subfragment = TRY(subrange->extract());
@@ -918,7 +918,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> Range::clone_contents()
 WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> Range::clone_the_contents()
 {
     // 1. Let fragment be a new DocumentFragment node whose node document is range’s start node’s node document.
-    auto fragment = MUST_OR_THROW_OOM(heap().allocate<DOM::DocumentFragment>(realm(), const_cast<Document&>(start_container()->document())));
+    auto fragment = heap().allocate<DOM::DocumentFragment>(realm(), const_cast<Document&>(start_container()->document()));
 
     // 2. If range is collapsed, then return fragment.
     if (collapsed())
@@ -1018,7 +1018,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> Range::clone_the_content
         TRY(fragment->append_child(clone));
 
         // 3. Let subrange be a new live range whose start is (original start node, original start offset) and whose end is (first partially contained child, first partially contained child’s length).
-        auto subrange = TRY(Range::create(original_start_node, original_start_offset, *first_partially_contained_child, first_partially_contained_child->length()));
+        auto subrange = Range::create(original_start_node, original_start_offset, *first_partially_contained_child, first_partially_contained_child->length());
 
         // 4. Let subfragment be the result of cloning the contents of subrange.
         auto subfragment = TRY(subrange->clone_the_contents());
@@ -1057,7 +1057,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DocumentFragment>> Range::clone_the_content
         TRY(fragment->append_child(clone));
 
         // 3. Let subrange be a new live range whose start is (last partially contained child, 0) and whose end is (original end node, original end offset).
-        auto subrange = TRY(Range::create(*last_partially_contained_child, 0, original_end_node, original_end_offset));
+        auto subrange = Range::create(*last_partially_contained_child, 0, original_end_node, original_end_offset);
 
         // 4. Let subfragment be the result of cloning the contents of subrange.
         auto subfragment = TRY(subrange->clone_the_contents());
diff --git a/Userland/Libraries/LibWeb/DOM/Range.h b/Userland/Libraries/LibWeb/DOM/Range.h
index 1a24e922b5a..97f20f852af 100644
--- a/Userland/Libraries/LibWeb/DOM/Range.h
+++ b/Userland/Libraries/LibWeb/DOM/Range.h
@@ -26,9 +26,9 @@ class Range final : public AbstractRange {
     WEB_PLATFORM_OBJECT(Range, AbstractRange);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Range>> create(Document&);
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Range>> create(HTML::Window&);
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Range>> create(Node& start_container, u32 start_offset, Node& end_container, u32 end_offset);
+    [[nodiscard]] static JS::NonnullGCPtr<Range> create(Document&);
+    [[nodiscard]] static JS::NonnullGCPtr<Range> create(HTML::Window&);
+    [[nodiscard]] static JS::NonnullGCPtr<Range> create(Node& start_container, u32 start_offset, Node& end_container, u32 end_offset);
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<Range>> construct_impl(JS::Realm&);
 
     virtual ~Range() override;
diff --git a/Userland/Libraries/LibWeb/DOM/StaticNodeList.cpp b/Userland/Libraries/LibWeb/DOM/StaticNodeList.cpp
index 03821977f4c..591616e8c2e 100644
--- a/Userland/Libraries/LibWeb/DOM/StaticNodeList.cpp
+++ b/Userland/Libraries/LibWeb/DOM/StaticNodeList.cpp
@@ -10,9 +10,9 @@
 
 namespace Web::DOM {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<NodeList>> StaticNodeList::create(JS::Realm& realm, Vector<JS::Handle<Node>> static_nodes)
+JS::NonnullGCPtr<NodeList> StaticNodeList::create(JS::Realm& realm, Vector<JS::Handle<Node>> static_nodes)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<StaticNodeList>(realm, realm, move(static_nodes)));
+    return realm.heap().allocate<StaticNodeList>(realm, realm, move(static_nodes));
 }
 
 StaticNodeList::StaticNodeList(JS::Realm& realm, Vector<JS::Handle<Node>> static_nodes)
diff --git a/Userland/Libraries/LibWeb/DOM/StaticNodeList.h b/Userland/Libraries/LibWeb/DOM/StaticNodeList.h
index 46997e9f98b..86f6c15db98 100644
--- a/Userland/Libraries/LibWeb/DOM/StaticNodeList.h
+++ b/Userland/Libraries/LibWeb/DOM/StaticNodeList.h
@@ -15,7 +15,7 @@ class StaticNodeList final : public NodeList {
     WEB_PLATFORM_OBJECT(StaticNodeList, NodeList);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<NodeList>> create(JS::Realm&, Vector<JS::Handle<Node>>);
+    [[nodiscard]] static JS::NonnullGCPtr<NodeList> create(JS::Realm&, Vector<JS::Handle<Node>>);
 
     virtual ~StaticNodeList() override;
 
diff --git a/Userland/Libraries/LibWeb/DOM/StaticRange.cpp b/Userland/Libraries/LibWeb/DOM/StaticRange.cpp
index 1aec3b20819..41f6722a2a7 100644
--- a/Userland/Libraries/LibWeb/DOM/StaticRange.cpp
+++ b/Userland/Libraries/LibWeb/DOM/StaticRange.cpp
@@ -32,7 +32,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<StaticRange>> StaticRange::construct_impl(J
         return WebIDL::InvalidNodeTypeError::create(realm, "endContainer cannot be a DocumentType or Attribute node.");
 
     // 2. Set this’s start to (init["startContainer"], init["startOffset"]) and end to (init["endContainer"], init["endOffset"]).
-    return MUST_OR_THROW_OOM(realm.heap().allocate<StaticRange>(realm, *init.start_container, init.start_offset, *init.end_container, init.end_offset));
+    return realm.heap().allocate<StaticRange>(realm, *init.start_container, init.start_offset, *init.end_container, init.end_offset);
 }
 
 void StaticRange::initialize(JS::Realm& realm)
diff --git a/Userland/Libraries/LibWeb/DOM/Text.cpp b/Userland/Libraries/LibWeb/DOM/Text.cpp
index ef0280352fe..0a86ebe852a 100644
--- a/Userland/Libraries/LibWeb/DOM/Text.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Text.cpp
@@ -41,7 +41,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Text>> Text::construct_impl(JS::Realm& real
 {
     // The new Text(data) constructor steps are to set this’s data to data and this’s node document to current global object’s associated Document.
     auto& window = verify_cast<HTML::Window>(HTML::current_global_object());
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Text>(realm, window.associated_document(), data));
+    return realm.heap().allocate<Text>(realm, window.associated_document(), data);
 }
 
 void Text::set_owner_input_element(Badge<HTML::HTMLInputElement>, HTML::HTMLInputElement& input_element)
@@ -67,7 +67,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Text>> Text::split_text(size_t offset)
     auto new_data = TRY(substring_data(offset, count));
 
     // 5. Let new node be a new Text node, with the same node document as node. Set new node’s data to new data.
-    auto new_node = MUST_OR_THROW_OOM(heap().allocate<Text>(realm(), document(), new_data));
+    auto new_node = heap().allocate<Text>(realm(), document(), new_data);
 
     // 6. Let parent be node’s parent.
     JS::GCPtr<Node> parent = this->parent();
diff --git a/Userland/Libraries/LibWeb/DOM/TreeWalker.cpp b/Userland/Libraries/LibWeb/DOM/TreeWalker.cpp
index fec61ba5ffd..e86a8a50b31 100644
--- a/Userland/Libraries/LibWeb/DOM/TreeWalker.cpp
+++ b/Userland/Libraries/LibWeb/DOM/TreeWalker.cpp
@@ -37,12 +37,12 @@ void TreeWalker::visit_edges(Cell::Visitor& visitor)
 }
 
 // https://dom.spec.whatwg.org/#dom-document-createtreewalker
-WebIDL::ExceptionOr<JS::NonnullGCPtr<TreeWalker>> TreeWalker::create(Node& root, unsigned what_to_show, JS::GCPtr<NodeFilter> filter)
+JS::NonnullGCPtr<TreeWalker> TreeWalker::create(Node& root, unsigned what_to_show, JS::GCPtr<NodeFilter> filter)
 {
     // 1. Let walker be a new TreeWalker object.
     // 2. Set walker’s root and walker’s current to root.
     auto& realm = root.realm();
-    auto walker = MUST_OR_THROW_OOM(realm.heap().allocate<TreeWalker>(realm, root));
+    auto walker = realm.heap().allocate<TreeWalker>(realm, root);
 
     // 3. Set walker’s whatToShow to whatToShow.
     walker->m_what_to_show = what_to_show;
diff --git a/Userland/Libraries/LibWeb/DOM/TreeWalker.h b/Userland/Libraries/LibWeb/DOM/TreeWalker.h
index 65c3e7ee0e2..b6e182ff7db 100644
--- a/Userland/Libraries/LibWeb/DOM/TreeWalker.h
+++ b/Userland/Libraries/LibWeb/DOM/TreeWalker.h
@@ -15,7 +15,7 @@ class TreeWalker final : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(TreeWalker, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<TreeWalker>> create(Node& root, unsigned what_to_show, JS::GCPtr<NodeFilter>);
+    [[nodiscard]] static JS::NonnullGCPtr<TreeWalker> create(Node& root, unsigned what_to_show, JS::GCPtr<NodeFilter>);
 
     virtual ~TreeWalker() override;
 
diff --git a/Userland/Libraries/LibWeb/DOMParsing/InnerHTML.cpp b/Userland/Libraries/LibWeb/DOMParsing/InnerHTML.cpp
index cd5d2e03e66..cefafb2d8fc 100644
--- a/Userland/Libraries/LibWeb/DOMParsing/InnerHTML.cpp
+++ b/Userland/Libraries/LibWeb/DOMParsing/InnerHTML.cpp
@@ -21,7 +21,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DOM::DocumentFragment>> parse_fragment(Depr
     auto& realm = context_element.realm();
 
     auto new_children = HTML::HTMLParser::parse_html_fragment(context_element, markup);
-    auto fragment = MUST_OR_THROW_OOM(realm.heap().allocate<DOM::DocumentFragment>(realm, context_element.document()));
+    auto fragment = realm.heap().allocate<DOM::DocumentFragment>(realm, context_element.document());
 
     for (auto& child : new_children) {
         // I don't know if this can throw here, but let's be safe.
diff --git a/Userland/Libraries/LibWeb/DOMParsing/XMLSerializer.cpp b/Userland/Libraries/LibWeb/DOMParsing/XMLSerializer.cpp
index e94f5235eb1..820ad9aac5a 100644
--- a/Userland/Libraries/LibWeb/DOMParsing/XMLSerializer.cpp
+++ b/Userland/Libraries/LibWeb/DOMParsing/XMLSerializer.cpp
@@ -25,7 +25,7 @@ namespace Web::DOMParsing {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<XMLSerializer>> XMLSerializer::construct_impl(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<XMLSerializer>(realm, realm));
+    return realm.heap().allocate<XMLSerializer>(realm, realm);
 }
 
 XMLSerializer::XMLSerializer(JS::Realm& realm)
diff --git a/Userland/Libraries/LibWeb/Encoding/TextDecoder.cpp b/Userland/Libraries/LibWeb/Encoding/TextDecoder.cpp
index 6f8b29da7eb..cb1a10cbe32 100644
--- a/Userland/Libraries/LibWeb/Encoding/TextDecoder.cpp
+++ b/Userland/Libraries/LibWeb/Encoding/TextDecoder.cpp
@@ -20,7 +20,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<TextDecoder>> TextDecoder::construct_impl(J
     if (!decoder.has_value())
         return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, TRY_OR_THROW_OOM(vm, String::formatted("Invalid encoding {}", encoding)) };
 
-    return MUST_OR_THROW_OOM(realm.heap().allocate<TextDecoder>(realm, realm, *decoder, move(encoding), false, false));
+    return realm.heap().allocate<TextDecoder>(realm, realm, *decoder, move(encoding), false, false);
 }
 
 // https://encoding.spec.whatwg.org/#dom-textdecoder
diff --git a/Userland/Libraries/LibWeb/Encoding/TextEncoder.cpp b/Userland/Libraries/LibWeb/Encoding/TextEncoder.cpp
index cb60a63ee8c..f2a21b28d2f 100644
--- a/Userland/Libraries/LibWeb/Encoding/TextEncoder.cpp
+++ b/Userland/Libraries/LibWeb/Encoding/TextEncoder.cpp
@@ -14,7 +14,7 @@ namespace Web::Encoding {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<TextEncoder>> TextEncoder::construct_impl(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<TextEncoder>(realm, realm));
+    return realm.heap().allocate<TextEncoder>(realm, realm);
 }
 
 TextEncoder::TextEncoder(JS::Realm& realm)
diff --git a/Userland/Libraries/LibWeb/Fetch/Body.cpp b/Userland/Libraries/LibWeb/Fetch/Body.cpp
index 7596f2a6635..601f3293554 100644
--- a/Userland/Libraries/LibWeb/Fetch/Body.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/Body.cpp
@@ -113,7 +113,7 @@ WebIDL::ExceptionOr<JS::Value> package_data(JS::Realm& realm, ByteBuffer bytes,
         // Return a Blob whose contents are bytes and type attribute is mimeType.
         // NOTE: If extracting the mime type returns failure, other browsers set it to an empty string - not sure if that's spec'd.
         auto mime_type_string = mime_type.has_value() ? TRY_OR_THROW_OOM(vm, mime_type->serialized()) : String {};
-        return TRY(FileAPI::Blob::create(realm, move(bytes), move(mime_type_string)));
+        return FileAPI::Blob::create(realm, move(bytes), move(mime_type_string));
     }
     case PackageDataType::FormData:
         // If mimeType’s essence is "multipart/form-data", then:
diff --git a/Userland/Libraries/LibWeb/Fetch/BodyInit.cpp b/Userland/Libraries/LibWeb/Fetch/BodyInit.cpp
index b116de67f3c..d136d1a50d6 100644
--- a/Userland/Libraries/LibWeb/Fetch/BodyInit.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/BodyInit.cpp
@@ -45,12 +45,12 @@ WebIDL::ExceptionOr<Infrastructure::BodyWithType> extract_body(JS::Realm& realm,
     else if (auto const* blob_handle = object.get_pointer<JS::Handle<FileAPI::Blob>>()) {
         // FIXME: "set stream to the result of running object’s get stream"
         (void)blob_handle;
-        stream = MUST_OR_THROW_OOM(realm.heap().allocate<Streams::ReadableStream>(realm, realm));
+        stream = realm.heap().allocate<Streams::ReadableStream>(realm, realm);
     }
     // 4. Otherwise, set stream to a new ReadableStream object, and set up stream.
     else {
         // FIXME: "set up stream"
-        stream = MUST_OR_THROW_OOM(realm.heap().allocate<Streams::ReadableStream>(realm, realm));
+        stream = realm.heap().allocate<Streams::ReadableStream>(realm, realm);
     }
 
     // 5. Assert: stream is a ReadableStream object.
diff --git a/Userland/Libraries/LibWeb/Fetch/FetchMethod.cpp b/Userland/Libraries/LibWeb/Fetch/FetchMethod.cpp
index 28afe8da7da..e9657cf1c0d 100644
--- a/Userland/Libraries/LibWeb/Fetch/FetchMethod.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/FetchMethod.cpp
@@ -111,7 +111,7 @@ JS::NonnullGCPtr<JS::Promise> fetch(JS::VM& vm, RequestInfo const& input, Reques
 
         // 4. Set responseObject to the result of creating a Response object, given response, "immutable", and
         //    relevantRealm.
-        auto response_object = Response::create(relevant_realm, response, Headers::Guard::Immutable).release_value_but_fixme_should_propagate_errors();
+        auto response_object = Response::create(relevant_realm, response, Headers::Guard::Immutable);
         response_object_handle = JS::make_handle(response_object);
 
         // 5. Resolve p with responseObject.
diff --git a/Userland/Libraries/LibWeb/Fetch/Fetching/Fetching.cpp b/Userland/Libraries/LibWeb/Fetch/Fetching/Fetching.cpp
index 61097dd4898..cd0fbcd0f95 100644
--- a/Userland/Libraries/LibWeb/Fetch/Fetching/Fetching.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/Fetching/Fetching.cpp
@@ -859,7 +859,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<PendingResponse>> http_fetch(JS::Realm& rea
     // 4. If request’s service-workers mode is "all", then:
     if (request->service_workers_mode() == Infrastructure::Request::ServiceWorkersMode::All) {
         // 1. Let requestForServiceWorker be a clone of request.
-        auto request_for_service_worker = TRY(request->clone(realm));
+        auto request_for_service_worker = request->clone(realm);
 
         // 2. If requestForServiceWorker’s body is non-null, then:
         if (!request_for_service_worker->body().has<Empty>()) {
@@ -1262,7 +1262,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<PendingResponse>> http_network_or_cache_fet
             // NOTE: Implementations are encouraged to avoid teeing request’s body’s stream when request’s body’s
             //       source is null as only a single body is needed in that case. E.g., when request’s body’s source
             //       is null, redirects and authentication will end up failing the fetch.
-            http_request = TRY(request->clone(realm));
+            http_request = request->clone(realm);
 
             // 2. Set httpFetchParams to a copy of fetchParams.
             // 3. Set httpFetchParams’s request to httpRequest.
diff --git a/Userland/Libraries/LibWeb/Fetch/Headers.cpp b/Userland/Libraries/LibWeb/Fetch/Headers.cpp
index eeaf89249a7..3c5a5e721dd 100644
--- a/Userland/Libraries/LibWeb/Fetch/Headers.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/Headers.cpp
@@ -17,7 +17,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Headers>> Headers::construct_impl(JS::Realm
     auto& vm = realm.vm();
 
     // The new Headers(init) constructor steps are:
-    auto headers = MUST_OR_THROW_OOM(realm.heap().allocate<Headers>(realm, realm, Infrastructure::HeaderList::create(vm)));
+    auto headers = realm.heap().allocate<Headers>(realm, realm, Infrastructure::HeaderList::create(vm));
 
     // 1. Set this’s guard to "none".
     headers->m_guard = Guard::None;
diff --git a/Userland/Libraries/LibWeb/Fetch/HeadersIterator.cpp b/Userland/Libraries/LibWeb/Fetch/HeadersIterator.cpp
index 729026042a4..cdbdc289553 100644
--- a/Userland/Libraries/LibWeb/Fetch/HeadersIterator.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/HeadersIterator.cpp
@@ -15,7 +15,7 @@ namespace Web::Bindings {
 template<>
 void Intrinsics::create_web_prototype_and_constructor<HeadersIteratorPrototype>(JS::Realm& realm)
 {
-    auto prototype = heap().allocate<HeadersIteratorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    auto prototype = heap().allocate<HeadersIteratorPrototype>(realm, realm);
     m_prototypes.set("HeadersIterator"sv, prototype);
 }
 
@@ -23,9 +23,9 @@ void Intrinsics::create_web_prototype_and_constructor<HeadersIteratorPrototype>(
 
 namespace Web::Fetch {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<HeadersIterator>> HeadersIterator::create(Headers const& headers, JS::Object::PropertyKind iteration_kind)
+JS::NonnullGCPtr<HeadersIterator> HeadersIterator::create(Headers const& headers, JS::Object::PropertyKind iteration_kind)
 {
-    return MUST_OR_THROW_OOM(headers.heap().allocate<HeadersIterator>(headers.realm(), headers, iteration_kind));
+    return headers.heap().allocate<HeadersIterator>(headers.realm(), headers, iteration_kind);
 }
 
 HeadersIterator::HeadersIterator(Headers const& headers, JS::Object::PropertyKind iteration_kind)
diff --git a/Userland/Libraries/LibWeb/Fetch/HeadersIterator.h b/Userland/Libraries/LibWeb/Fetch/HeadersIterator.h
index 6375a405608..575abf97eaa 100644
--- a/Userland/Libraries/LibWeb/Fetch/HeadersIterator.h
+++ b/Userland/Libraries/LibWeb/Fetch/HeadersIterator.h
@@ -16,7 +16,7 @@ class HeadersIterator final : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(HeadersIterator, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<HeadersIterator>> create(Headers const&, JS::Object::PropertyKind iteration_kind);
+    [[nodiscard]] static JS::NonnullGCPtr<HeadersIterator> create(Headers const&, JS::Object::PropertyKind iteration_kind);
 
     virtual ~HeadersIterator() override;
 
diff --git a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Bodies.cpp b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Bodies.cpp
index 5c7ee0c8c07..bb6aedee651 100644
--- a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Bodies.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Bodies.cpp
@@ -26,12 +26,12 @@ Body::Body(JS::Handle<Streams::ReadableStream> stream, SourceType source, Option
 }
 
 // https://fetch.spec.whatwg.org/#concept-body-clone
-WebIDL::ExceptionOr<Body> Body::clone(JS::Realm& realm) const
+Body Body::clone(JS::Realm& realm) const
 {
     // To clone a body body, run these steps:
     // FIXME: 1. Let « out1, out2 » be the result of teeing body’s stream.
     // FIXME: 2. Set body’s stream to out1.
-    auto out2 = MUST_OR_THROW_OOM(realm.heap().allocate<Streams::ReadableStream>(realm, realm));
+    auto out2 = realm.heap().allocate<Streams::ReadableStream>(realm, realm);
 
     // 3. Return a body whose stream is out2 and other members are copied from body.
     return Body { JS::make_handle(out2), m_source, m_length };
diff --git a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Bodies.h b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Bodies.h
index ff40d57ebe7..ddf93a08dfd 100644
--- a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Bodies.h
+++ b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Bodies.h
@@ -36,7 +36,7 @@ public:
     [[nodiscard]] SourceType const& source() const { return m_source; }
     [[nodiscard]] Optional<u64> const& length() const { return m_length; }
 
-    WebIDL::ExceptionOr<Body> clone(JS::Realm&) const;
+    [[nodiscard]] Body clone(JS::Realm&) const;
 
     WebIDL::ExceptionOr<void> fully_read(JS::Realm&, ProcessBodyCallback process_body, ProcessBodyErrorCallback process_body_error, TaskDestination task_destination) const;
 
diff --git a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Requests.cpp b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Requests.cpp
index 0c3bc57bbaa..3a6a3a2d660 100644
--- a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Requests.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Requests.cpp
@@ -202,7 +202,7 @@ ErrorOr<ByteBuffer> Request::byte_serialize_origin() const
 }
 
 // https://fetch.spec.whatwg.org/#concept-request-clone
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Request>> Request::clone(JS::Realm& realm) const
+JS::NonnullGCPtr<Request> Request::clone(JS::Realm& realm) const
 {
     // To clone a request request, run these steps:
     auto& vm = realm.vm();
@@ -250,7 +250,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Request>> Request::clone(JS::Realm& realm)
 
     // 2. If request’s body is non-null, set newRequest’s body to the result of cloning request’s body.
     if (auto const* body = m_body.get_pointer<Body>())
-        new_request->set_body(TRY(body->clone(realm)));
+        new_request->set_body(body->clone(realm));
 
     // 3. Return newRequest.
     return new_request;
diff --git a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Requests.h b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Requests.h
index 7f1e4feff00..30ce01bb81e 100644
--- a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Requests.h
+++ b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Requests.h
@@ -297,7 +297,7 @@ public:
     [[nodiscard]] ErrorOr<String> serialize_origin() const;
     [[nodiscard]] ErrorOr<ByteBuffer> byte_serialize_origin() const;
 
-    [[nodiscard]] WebIDL::ExceptionOr<JS::NonnullGCPtr<Request>> clone(JS::Realm&) const;
+    [[nodiscard]] JS::NonnullGCPtr<Request> clone(JS::Realm&) const;
 
     [[nodiscard]] ErrorOr<void> add_range_header(u64 first, Optional<u64> const& last);
     [[nodiscard]] ErrorOr<void> add_origin_header();
diff --git a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Responses.cpp b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Responses.cpp
index 527b735c22b..18ef9bf8a77 100644
--- a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Responses.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Responses.cpp
@@ -164,7 +164,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> Response::clone(JS::Realm& realm
 
     // 3. If response’s body is non-null, then set newResponse’s body to the result of cloning response’s body.
     if (m_body.has_value())
-        new_response->set_body(TRY(m_body->clone(realm)));
+        new_response->set_body(m_body->clone(realm));
 
     // 4. Return newResponse.
     return new_response;
diff --git a/Userland/Libraries/LibWeb/Fetch/Request.cpp b/Userland/Libraries/LibWeb/Fetch/Request.cpp
index c1dfb3fbbf0..e6fec92a4fb 100644
--- a/Userland/Libraries/LibWeb/Fetch/Request.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/Request.cpp
@@ -79,18 +79,18 @@ Optional<Infrastructure::Body&> Request::body_impl()
 }
 
 // https://fetch.spec.whatwg.org/#request-create
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Request>> Request::create(JS::Realm& realm, JS::NonnullGCPtr<Infrastructure::Request> request, Headers::Guard guard)
+JS::NonnullGCPtr<Request> Request::create(JS::Realm& realm, JS::NonnullGCPtr<Infrastructure::Request> request, Headers::Guard guard)
 {
     // 1. Let requestObject be a new Request object with realm.
     // 2. Set requestObject’s request to request.
-    auto request_object = MUST_OR_THROW_OOM(realm.heap().allocate<Request>(realm, realm, request));
+    auto request_object = realm.heap().allocate<Request>(realm, realm, request);
 
     // 3. Set requestObject’s headers to a new Headers object with realm, whose headers list is request’s headers list and guard is guard.
-    request_object->m_headers = MUST_OR_THROW_OOM(realm.heap().allocate<Headers>(realm, realm, request->header_list()));
+    request_object->m_headers = realm.heap().allocate<Headers>(realm, realm, request->header_list());
     request_object->m_headers->set_guard(guard);
 
     // 4. Set requestObject’s signal to a new AbortSignal object with realm.
-    request_object->m_signal = MUST_OR_THROW_OOM(realm.heap().allocate<DOM::AbortSignal>(realm, realm));
+    request_object->m_signal = realm.heap().allocate<DOM::AbortSignal>(realm, realm);
 
     // 5. Return requestObject.
     return request_object;
@@ -102,7 +102,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Request>> Request::construct_impl(JS::Realm
     auto& vm = realm.vm();
 
     // Referred to as 'this' in the spec.
-    auto request_object = MUST_OR_THROW_OOM(realm.heap().allocate<Request>(realm, realm, Infrastructure::Request::create(vm)));
+    auto request_object = realm.heap().allocate<Request>(realm, realm, Infrastructure::Request::create(vm));
 
     // 1. Let request be null.
     JS::GCPtr<Infrastructure::Request> input_request;
@@ -387,14 +387,14 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Request>> Request::construct_impl(JS::Realm
 
     // 28. Set this’s signal to a new AbortSignal object with this’s relevant Realm.
     auto& this_relevant_realm = HTML::relevant_realm(*request_object);
-    request_object->m_signal = MUST_OR_THROW_OOM(realm.heap().allocate<DOM::AbortSignal>(this_relevant_realm, this_relevant_realm));
+    request_object->m_signal = realm.heap().allocate<DOM::AbortSignal>(this_relevant_realm, this_relevant_realm);
 
     // 29. If signal is not null, then make this’s signal follow signal.
     if (input_signal != nullptr)
         request_object->m_signal->follow(*input_signal);
 
     // 30. Set this’s headers to a new Headers object with this’s relevant Realm, whose header list is request’s header list and guard is "request".
-    request_object->m_headers = MUST_OR_THROW_OOM(realm.heap().allocate<Headers>(realm, realm, request->header_list()));
+    request_object->m_headers = realm.heap().allocate<Headers>(realm, realm, request->header_list());
     request_object->m_headers->set_guard(Headers::Guard::Request);
 
     // 31. If this’s request’s mode is "no-cors", then:
@@ -639,10 +639,10 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Request>> Request::clone() const
         return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, "Request is unusable"sv };
 
     // 2. Let clonedRequest be the result of cloning this’s request.
-    auto cloned_request = TRY(m_request->clone(realm));
+    auto cloned_request = m_request->clone(realm);
 
     // 3. Let clonedRequestObject be the result of creating a Request object, given clonedRequest, this’s headers’s guard, and this’s relevant Realm.
-    auto cloned_request_object = TRY(Request::create(HTML::relevant_realm(*this), cloned_request, m_headers->guard()));
+    auto cloned_request_object = Request::create(HTML::relevant_realm(*this), cloned_request, m_headers->guard());
 
     // 4. Make clonedRequestObject’s signal follow this’s signal.
     cloned_request_object->m_signal->follow(*m_signal);
diff --git a/Userland/Libraries/LibWeb/Fetch/Request.h b/Userland/Libraries/LibWeb/Fetch/Request.h
index f5a923c8195..7b74776bbb3 100644
--- a/Userland/Libraries/LibWeb/Fetch/Request.h
+++ b/Userland/Libraries/LibWeb/Fetch/Request.h
@@ -66,7 +66,7 @@ class Request final
     WEB_PLATFORM_OBJECT(Request, Bindings::PlatformObject);
 
 public:
-    [[nodiscard]] static WebIDL::ExceptionOr<JS::NonnullGCPtr<Request>> create(JS::Realm&, JS::NonnullGCPtr<Infrastructure::Request>, Headers::Guard);
+    [[nodiscard]] static JS::NonnullGCPtr<Request> create(JS::Realm&, JS::NonnullGCPtr<Infrastructure::Request>, Headers::Guard);
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<Request>> construct_impl(JS::Realm&, RequestInfo const& input, RequestInit const& init = {});
 
     virtual ~Request() override;
diff --git a/Userland/Libraries/LibWeb/Fetch/Response.cpp b/Userland/Libraries/LibWeb/Fetch/Response.cpp
index 82526baa8bf..e9b528cac94 100644
--- a/Userland/Libraries/LibWeb/Fetch/Response.cpp
+++ b/Userland/Libraries/LibWeb/Fetch/Response.cpp
@@ -71,14 +71,14 @@ Optional<Infrastructure::Body&> Response::body_impl()
 }
 
 // https://fetch.spec.whatwg.org/#response-create
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> Response::create(JS::Realm& realm, JS::NonnullGCPtr<Infrastructure::Response> response, Headers::Guard guard)
+JS::NonnullGCPtr<Response> Response::create(JS::Realm& realm, JS::NonnullGCPtr<Infrastructure::Response> response, Headers::Guard guard)
 {
     // 1. Let responseObject be a new Response object with realm.
     // 2. Set responseObject’s response to response.
-    auto response_object = MUST_OR_THROW_OOM(realm.heap().allocate<Response>(realm, realm, response));
+    auto response_object = realm.heap().allocate<Response>(realm, realm, response);
 
     // 3. Set responseObject’s headers to a new Headers object with realm, whose headers list is response’s headers list and guard is guard.
-    response_object->m_headers = MUST_OR_THROW_OOM(realm.heap().allocate<Headers>(realm, realm, response->header_list()));
+    response_object->m_headers = realm.heap().allocate<Headers>(realm, realm, response->header_list());
     response_object->m_headers->set_guard(guard);
 
     // 4. Return responseObject.
@@ -134,14 +134,14 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> Response::construct_impl(JS::Rea
     auto& vm = realm.vm();
 
     // Referred to as 'this' in the spec.
-    auto response_object = MUST_OR_THROW_OOM(realm.heap().allocate<Response>(realm, realm, Infrastructure::Response::create(vm)));
+    auto response_object = realm.heap().allocate<Response>(realm, realm, Infrastructure::Response::create(vm));
 
     // 1. Set this’s response to a new response.
     // NOTE: This is done at the beginning as the 'this' value Response object
     //       cannot exist with a null Infrastructure::Response.
 
     // 2. Set this’s headers to a new Headers object with this’s relevant Realm, whose header list is this’s response’s header list and guard is "response".
-    response_object->m_headers = MUST_OR_THROW_OOM(realm.heap().allocate<Headers>(realm, realm, response_object->response()->header_list()));
+    response_object->m_headers = realm.heap().allocate<Headers>(realm, realm, response_object->response()->header_list());
     response_object->m_headers->set_guard(Headers::Guard::Response);
 
     // 3. Let bodyWithType be null.
@@ -158,7 +158,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> Response::construct_impl(JS::Rea
 }
 
 // https://fetch.spec.whatwg.org/#dom-response-error
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> Response::error(JS::VM& vm)
+JS::NonnullGCPtr<Response> Response::error(JS::VM& vm)
 {
     // The static error() method steps are to return the result of creating a Response object, given a new network error, "immutable", and this’s relevant Realm.
     // FIXME: How can we reliably get 'this', i.e. the object the function was called on, in IDL-defined functions?
@@ -184,7 +184,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> Response::redirect(JS::VM& vm, S
 
     // 4. Let responseObject be the result of creating a Response object, given a new response, "immutable", and this’s relevant Realm.
     // FIXME: How can we reliably get 'this', i.e. the object the function was called on, in IDL-defined functions?
-    auto response_object = TRY(Response::create(realm, Infrastructure::Response::create(vm), Headers::Guard::Immutable));
+    auto response_object = Response::create(realm, Infrastructure::Response::create(vm), Headers::Guard::Immutable);
 
     // 5. Set responseObject’s response’s status to status.
     response_object->response()->set_status(status);
@@ -213,7 +213,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> Response::json(JS::VM& vm, JS::V
 
     // 3. Let responseObject be the result of creating a Response object, given a new response, "response", and this’s relevant Realm.
     // FIXME: How can we reliably get 'this', i.e. the object the function was called on, in IDL-defined functions?
-    auto response_object = TRY(Response::create(realm, Infrastructure::Response::create(vm), Headers::Guard::Response));
+    auto response_object = Response::create(realm, Infrastructure::Response::create(vm), Headers::Guard::Response);
 
     // 4. Perform initialize a response given responseObject, init, and (body, "application/json").
     auto body_with_type = Infrastructure::BodyWithType {
@@ -294,7 +294,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> Response::clone() const
     auto cloned_response = TRY(m_response->clone(realm));
 
     // 3. Return the result of creating a Response object, given clonedResponse, this’s headers’s guard, and this’s relevant Realm.
-    return TRY(Response::create(HTML::relevant_realm(*this), cloned_response, m_headers->guard()));
+    return Response::create(HTML::relevant_realm(*this), cloned_response, m_headers->guard());
 }
 
 }
diff --git a/Userland/Libraries/LibWeb/Fetch/Response.h b/Userland/Libraries/LibWeb/Fetch/Response.h
index bf42ffbd4f4..dc346630056 100644
--- a/Userland/Libraries/LibWeb/Fetch/Response.h
+++ b/Userland/Libraries/LibWeb/Fetch/Response.h
@@ -33,7 +33,7 @@ class Response final
     WEB_PLATFORM_OBJECT(Response, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> create(JS::Realm&, JS::NonnullGCPtr<Infrastructure::Response>, Headers::Guard);
+    [[nodiscard]] static JS::NonnullGCPtr<Response> create(JS::Realm&, JS::NonnullGCPtr<Infrastructure::Response>, Headers::Guard);
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> construct_impl(JS::Realm&, Optional<BodyInit> const& body = {}, ResponseInit const& init = {});
 
     virtual ~Response() override;
@@ -48,7 +48,7 @@ public:
     [[nodiscard]] JS::NonnullGCPtr<Infrastructure::Response> response() const { return m_response; }
 
     // JS API functions
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> error(JS::VM&);
+    [[nodiscard]] static JS::NonnullGCPtr<Response> error(JS::VM&);
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> redirect(JS::VM&, String const& url, u16 status);
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<Response>> json(JS::VM&, JS::Value data, ResponseInit const& init = {});
     [[nodiscard]] Bindings::ResponseType type() const;
diff --git a/Userland/Libraries/LibWeb/FileAPI/Blob.cpp b/Userland/Libraries/LibWeb/FileAPI/Blob.cpp
index d8ba7732e04..cc8124b57b0 100644
--- a/Userland/Libraries/LibWeb/FileAPI/Blob.cpp
+++ b/Userland/Libraries/LibWeb/FileAPI/Blob.cpp
@@ -22,9 +22,9 @@
 
 namespace Web::FileAPI {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Blob>> Blob::create(JS::Realm& realm, ByteBuffer byte_buffer, String type)
+JS::NonnullGCPtr<Blob> Blob::create(JS::Realm& realm, ByteBuffer byte_buffer, String type)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Blob>(realm, realm, move(byte_buffer), move(type)));
+    return realm.heap().allocate<Blob>(realm, realm, move(byte_buffer), move(type));
 }
 
 // https://w3c.github.io/FileAPI/#convert-line-endings-to-native
@@ -146,18 +146,16 @@ void Blob::initialize(JS::Realm& realm)
 }
 
 // https://w3c.github.io/FileAPI/#ref-for-dom-blob-blob
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Blob>> Blob::create(JS::Realm& realm, Optional<Vector<BlobPart>> const& blob_parts, Optional<BlobPropertyBag> const& options)
+JS::NonnullGCPtr<Blob> Blob::create(JS::Realm& realm, Optional<Vector<BlobPart>> const& blob_parts, Optional<BlobPropertyBag> const& options)
 {
-    auto& vm = realm.vm();
-
     // 1. If invoked with zero parameters, return a new Blob object consisting of 0 bytes, with size set to 0, and with type set to the empty string.
     if (!blob_parts.has_value() && !options.has_value())
-        return MUST_OR_THROW_OOM(realm.heap().allocate<Blob>(realm, realm));
+        return realm.heap().allocate<Blob>(realm, realm);
 
     ByteBuffer byte_buffer {};
     // 2. Let bytes be the result of processing blob parts given blobParts and options.
     if (blob_parts.has_value()) {
-        byte_buffer = TRY_OR_THROW_OOM(realm.vm(), process_blob_parts(blob_parts.value(), options));
+        byte_buffer = MUST(process_blob_parts(blob_parts.value(), options));
     }
 
     auto type = String {};
@@ -173,11 +171,11 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Blob>> Blob::create(JS::Realm& realm, Optio
 
         // 2. Convert every character in t to ASCII lowercase.
         if (!type.is_empty())
-            type = TRY_OR_THROW_OOM(vm, Infra::to_ascii_lowercase(type));
+            type = MUST(Infra::to_ascii_lowercase(type));
     }
 
     // 4. Return a Blob object referring to bytes as its associated byte sequence, with its size set to the length of bytes, and its type set to the value of t from the substeps above.
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Blob>(realm, realm, move(byte_buffer), move(type)));
+    return realm.heap().allocate<Blob>(realm, realm, move(byte_buffer), move(type));
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<Blob>> Blob::construct_impl(JS::Realm& realm, Optional<Vector<BlobPart>> const& blob_parts, Optional<BlobPropertyBag> const& options)
@@ -250,7 +248,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Blob>> Blob::slice(Optional<i64> start, Opt
     // b. S.size = span.
     // c. S.type = relativeContentType.
     auto byte_buffer = TRY_OR_THROW_OOM(vm, m_byte_buffer.slice(relative_start, span));
-    return MUST_OR_THROW_OOM(heap().allocate<Blob>(realm(), realm(), move(byte_buffer), move(relative_content_type)));
+    return heap().allocate<Blob>(realm(), realm(), move(byte_buffer), move(relative_content_type));
 }
 
 // https://w3c.github.io/FileAPI/#dom-blob-stream
@@ -266,7 +264,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Streams::ReadableStream>> Blob::get_stream(
     auto& realm = this->realm();
 
     // 1. Let stream be a new ReadableStream created in blob’s relevant Realm.
-    auto stream = MUST_OR_THROW_OOM(realm.heap().allocate<Streams::ReadableStream>(realm, realm));
+    auto stream = realm.heap().allocate<Streams::ReadableStream>(realm, realm);
 
     // 2. Set up stream with byte reading support.
     TRY(set_up_readable_stream_controller_with_byte_reading_support(stream));
diff --git a/Userland/Libraries/LibWeb/FileAPI/Blob.h b/Userland/Libraries/LibWeb/FileAPI/Blob.h
index 3657812022e..d4bbdfcabd5 100644
--- a/Userland/Libraries/LibWeb/FileAPI/Blob.h
+++ b/Userland/Libraries/LibWeb/FileAPI/Blob.h
@@ -32,8 +32,8 @@ class Blob : public Bindings::PlatformObject {
 public:
     virtual ~Blob() override;
 
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Blob>> create(JS::Realm&, ByteBuffer, String type);
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Blob>> create(JS::Realm&, Optional<Vector<BlobPart>> const& blob_parts = {}, Optional<BlobPropertyBag> const& options = {});
+    [[nodiscard]] static JS::NonnullGCPtr<Blob> create(JS::Realm&, ByteBuffer, String type);
+    [[nodiscard]] static JS::NonnullGCPtr<Blob> create(JS::Realm&, Optional<Vector<BlobPart>> const& blob_parts = {}, Optional<BlobPropertyBag> const& options = {});
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<Blob>> construct_impl(JS::Realm&, Optional<Vector<BlobPart>> const& blob_parts = {}, Optional<BlobPropertyBag> const& options = {});
 
     // https://w3c.github.io/FileAPI/#dfn-size
diff --git a/Userland/Libraries/LibWeb/FileAPI/File.cpp b/Userland/Libraries/LibWeb/FileAPI/File.cpp
index 679af049fd8..95a87c8ccfa 100644
--- a/Userland/Libraries/LibWeb/FileAPI/File.cpp
+++ b/Userland/Libraries/LibWeb/FileAPI/File.cpp
@@ -67,7 +67,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<File>> File::create(JS::Realm& realm, Vecto
     //    4. F.name is set to n.
     //    5. F.type is set to t.
     //    6. F.lastModified is set to d.
-    return MUST_OR_THROW_OOM(realm.heap().allocate<File>(realm, realm, move(bytes), move(name), move(type), last_modified));
+    return realm.heap().allocate<File>(realm, realm, move(bytes), move(name), move(type), last_modified);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<File>> File::construct_impl(JS::Realm& realm, Vector<BlobPart> const& file_bits, String const& file_name, Optional<FilePropertyBag> const& options)
diff --git a/Userland/Libraries/LibWeb/FileAPI/FileList.cpp b/Userland/Libraries/LibWeb/FileAPI/FileList.cpp
index 45fa1b075ee..ec259dbda0b 100644
--- a/Userland/Libraries/LibWeb/FileAPI/FileList.cpp
+++ b/Userland/Libraries/LibWeb/FileAPI/FileList.cpp
@@ -11,9 +11,9 @@
 
 namespace Web::FileAPI {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<FileList>> FileList::create(JS::Realm& realm, Vector<JS::NonnullGCPtr<File>>&& files)
+JS::NonnullGCPtr<FileList> FileList::create(JS::Realm& realm, Vector<JS::NonnullGCPtr<File>>&& files)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<FileList>(realm, realm, move(files)));
+    return realm.heap().allocate<FileList>(realm, realm, move(files));
 }
 
 FileList::FileList(JS::Realm& realm, Vector<JS::NonnullGCPtr<File>>&& files)
diff --git a/Userland/Libraries/LibWeb/FileAPI/FileList.h b/Userland/Libraries/LibWeb/FileAPI/FileList.h
index 98d90796b20..fe44e10d9b1 100644
--- a/Userland/Libraries/LibWeb/FileAPI/FileList.h
+++ b/Userland/Libraries/LibWeb/FileAPI/FileList.h
@@ -18,7 +18,7 @@ class FileList : public Bindings::LegacyPlatformObject {
     WEB_PLATFORM_OBJECT(FileList, Bindings::LegacyPlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<FileList>> create(JS::Realm&, Vector<JS::NonnullGCPtr<File>>&&);
+    [[nodiscard]] static JS::NonnullGCPtr<FileList> create(JS::Realm&, Vector<JS::NonnullGCPtr<File>>&&);
     virtual ~FileList() override;
 
     // https://w3c.github.io/FileAPI/#dfn-length
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMMatrix.cpp b/Userland/Libraries/LibWeb/Geometry/DOMMatrix.cpp
index 8c70f33f515..35c38f3bd76 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMMatrix.cpp
+++ b/Userland/Libraries/LibWeb/Geometry/DOMMatrix.cpp
@@ -23,7 +23,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMMatrix>> DOMMatrix::construct_impl(JS::R
             return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, TRY_OR_THROW_OOM(vm, String::formatted("Sequence must contain exactly 6 or 16 elements, got {} element(s)", double_sequence->size())) };
     }
 
-    return realm.heap().allocate<DOMMatrix>(realm, realm, init).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<DOMMatrix>(realm, realm, init);
 }
 
 // https://drafts.fxtf.org/geometry/#create-a-dommatrix-from-the-2d-dictionary
@@ -42,12 +42,12 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMMatrix>> DOMMatrix::create_from_dom_matr
 
     // 2. Return the result of invoking create a 2d matrix of type DOMMatrixReadOnly or DOMMatrix as appropriate, with a sequence of numbers,
     //    the values being the 6 elements m11, m12, m21, m22, m41 and m42 of other in the given order.
-    return realm.heap().allocate<DOMMatrix>(realm, realm, init.m11.value(), init.m12.value(), init.m21.value(), init.m22.value(), init.m41.value(), init.m42.value()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<DOMMatrix>(realm, realm, init.m11.value(), init.m12.value(), init.m21.value(), init.m22.value(), init.m41.value(), init.m42.value());
 }
 
 JS::NonnullGCPtr<DOMMatrix> DOMMatrix::create_from_dom_matrix_read_only(JS::Realm& realm, DOMMatrixReadOnly const& read_only_matrix)
 {
-    return realm.heap().allocate<DOMMatrix>(realm, realm, read_only_matrix).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<DOMMatrix>(realm, realm, read_only_matrix);
 }
 
 DOMMatrix::DOMMatrix(JS::Realm& realm, double m11, double m12, double m21, double m22, double m41, double m42)
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.cpp b/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.cpp
index a8bc8770092..b96dc1edb9c 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.cpp
+++ b/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.cpp
@@ -24,7 +24,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMMatrixReadOnly>> DOMMatrixReadOnly::cons
             return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, TRY_OR_THROW_OOM(vm, String::formatted("Sequence must contain exactly 6 or 16 elements, got {} element(s)", double_sequence->size())) };
     }
 
-    return realm.heap().allocate<DOMMatrixReadOnly>(realm, realm, init).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<DOMMatrixReadOnly>(realm, realm, init);
 }
 
 // https://drafts.fxtf.org/geometry/#create-a-dommatrixreadonly-from-the-2d-dictionary
@@ -43,7 +43,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMMatrixReadOnly>> DOMMatrixReadOnly::crea
 
     // 2. Return the result of invoking create a 2d matrix of type DOMMatrixReadOnly or DOMMatrix as appropriate, with a sequence of numbers,
     //    the values being the 6 elements m11, m12, m21, m22, m41 and m42 of other in the given order.
-    return realm.heap().allocate<DOMMatrixReadOnly>(realm, realm, init.m11.value(), init.m12.value(), init.m21.value(), init.m22.value(), init.m41.value(), init.m42.value()).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<DOMMatrixReadOnly>(realm, realm, init.m11.value(), init.m12.value(), init.m21.value(), init.m22.value(), init.m41.value(), init.m42.value());
 }
 
 DOMMatrixReadOnly::DOMMatrixReadOnly(JS::Realm& realm, double m11, double m12, double m21, double m22, double m41, double m42)
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMPoint.cpp b/Userland/Libraries/LibWeb/Geometry/DOMPoint.cpp
index a0de36ecefd..36bc79b80d8 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMPoint.cpp
+++ b/Userland/Libraries/LibWeb/Geometry/DOMPoint.cpp
@@ -13,7 +13,7 @@ namespace Web::Geometry {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMPoint>> DOMPoint::construct_impl(JS::Realm& realm, double x, double y, double z, double w)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<DOMPoint>(realm, realm, x, y, z, w));
+    return realm.heap().allocate<DOMPoint>(realm, realm, x, y, z, w);
 }
 
 DOMPoint::DOMPoint(JS::Realm& realm, double x, double y, double z, double w)
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMPointReadOnly.cpp b/Userland/Libraries/LibWeb/Geometry/DOMPointReadOnly.cpp
index 0ec52f7b3c2..07758bfac4e 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMPointReadOnly.cpp
+++ b/Userland/Libraries/LibWeb/Geometry/DOMPointReadOnly.cpp
@@ -13,7 +13,7 @@ namespace Web::Geometry {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMPointReadOnly>> DOMPointReadOnly::construct_impl(JS::Realm& realm, double x, double y, double z, double w)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<DOMPointReadOnly>(realm, realm, x, y, z, w));
+    return realm.heap().allocate<DOMPointReadOnly>(realm, realm, x, y, z, w);
 }
 
 DOMPointReadOnly::DOMPointReadOnly(JS::Realm& realm, double x, double y, double z, double w)
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMRect.cpp b/Userland/Libraries/LibWeb/Geometry/DOMRect.cpp
index bc179cb4310..f11b6f1786a 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMRect.cpp
+++ b/Userland/Libraries/LibWeb/Geometry/DOMRect.cpp
@@ -12,19 +12,19 @@ namespace Web::Geometry {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMRect>> DOMRect::construct_impl(JS::Realm& realm, double x, double y, double width, double height)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<DOMRect>(realm, realm, x, y, width, height));
+    return create(realm, Gfx::FloatRect { x, y, width, height });
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMRect>> DOMRect::create(JS::Realm& realm, Gfx::FloatRect const& rect)
+JS::NonnullGCPtr<DOMRect> DOMRect::create(JS::Realm& realm, Gfx::FloatRect const& rect)
 {
-    return construct_impl(realm, rect.x(), rect.y(), rect.width(), rect.height());
+    return realm.heap().allocate<DOMRect>(realm, realm, rect.x(), rect.y(), rect.width(), rect.height());
 }
 
 // https://drafts.fxtf.org/geometry/#create-a-domrect-from-the-dictionary
-WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMRect>> DOMRect::from_rect(JS::VM& vm, Geometry::DOMRectInit const& other)
+JS::NonnullGCPtr<DOMRect> DOMRect::from_rect(JS::VM& vm, Geometry::DOMRectInit const& other)
 {
     auto& realm = *vm.current_realm();
-    return MUST_OR_THROW_OOM(realm.heap().allocate<DOMRect>(realm, realm, other.x, other.y, other.width, other.height));
+    return realm.heap().allocate<DOMRect>(realm, realm, other.x, other.y, other.width, other.height);
 }
 
 DOMRect::DOMRect(JS::Realm& realm, double x, double y, double width, double height)
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMRect.h b/Userland/Libraries/LibWeb/Geometry/DOMRect.h
index c56708f57ec..4c41c866c4b 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMRect.h
+++ b/Userland/Libraries/LibWeb/Geometry/DOMRect.h
@@ -16,8 +16,8 @@ class DOMRect final : public DOMRectReadOnly {
 
 public:
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMRect>> construct_impl(JS::Realm&, double x = 0, double y = 0, double width = 0, double height = 0);
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMRect>> create(JS::Realm&, Gfx::FloatRect const&);
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMRect>> from_rect(JS::VM&, DOMRectInit const&);
+    [[nodiscard]] static JS::NonnullGCPtr<DOMRect> create(JS::Realm&, Gfx::FloatRect const&);
+    [[nodiscard]] static JS::NonnullGCPtr<DOMRect> from_rect(JS::VM&, DOMRectInit const&);
 
     virtual ~DOMRect() override;
 
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMRectList.cpp b/Userland/Libraries/LibWeb/Geometry/DOMRectList.cpp
index 28c8b997d5f..408ef100360 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMRectList.cpp
+++ b/Userland/Libraries/LibWeb/Geometry/DOMRectList.cpp
@@ -12,12 +12,12 @@
 
 namespace Web::Geometry {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMRectList>> DOMRectList::create(JS::Realm& realm, Vector<JS::Handle<DOMRect>> rect_handles)
+JS::NonnullGCPtr<DOMRectList> DOMRectList::create(JS::Realm& realm, Vector<JS::Handle<DOMRect>> rect_handles)
 {
     Vector<JS::NonnullGCPtr<DOMRect>> rects;
     for (auto& rect : rect_handles)
         rects.append(*rect);
-    return MUST_OR_THROW_OOM(realm.heap().allocate<DOMRectList>(realm, realm, move(rects)));
+    return realm.heap().allocate<DOMRectList>(realm, realm, move(rects));
 }
 
 DOMRectList::DOMRectList(JS::Realm& realm, Vector<JS::NonnullGCPtr<DOMRect>> rects)
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMRectList.h b/Userland/Libraries/LibWeb/Geometry/DOMRectList.h
index 77956b465eb..71385180912 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMRectList.h
+++ b/Userland/Libraries/LibWeb/Geometry/DOMRectList.h
@@ -18,7 +18,7 @@ class DOMRectList final : public Bindings::LegacyPlatformObject {
     WEB_PLATFORM_OBJECT(DOMRectList, Bindings::LegacyPlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMRectList>> create(JS::Realm&, Vector<JS::Handle<DOMRect>>);
+    [[nodiscard]] static JS::NonnullGCPtr<DOMRectList> create(JS::Realm&, Vector<JS::Handle<DOMRect>>);
 
     virtual ~DOMRectList() override;
 
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMRectReadOnly.cpp b/Userland/Libraries/LibWeb/Geometry/DOMRectReadOnly.cpp
index f84844e5619..2487f652eed 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMRectReadOnly.cpp
+++ b/Userland/Libraries/LibWeb/Geometry/DOMRectReadOnly.cpp
@@ -12,14 +12,14 @@ namespace Web::Geometry {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMRectReadOnly>> DOMRectReadOnly::construct_impl(JS::Realm& realm, double x, double y, double width, double height)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<DOMRectReadOnly>(realm, realm, x, y, width, height));
+    return realm.heap().allocate<DOMRectReadOnly>(realm, realm, x, y, width, height);
 }
 
 // https://drafts.fxtf.org/geometry/#create-a-domrect-from-the-dictionary
-WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMRectReadOnly>> DOMRectReadOnly::from_rect(JS::VM& vm, Geometry::DOMRectInit const& other)
+JS::NonnullGCPtr<DOMRectReadOnly> DOMRectReadOnly::from_rect(JS::VM& vm, Geometry::DOMRectInit const& other)
 {
     auto& realm = *vm.current_realm();
-    return MUST_OR_THROW_OOM(realm.heap().allocate<DOMRectReadOnly>(realm, realm, other.x, other.y, other.width, other.height));
+    return realm.heap().allocate<DOMRectReadOnly>(realm, realm, other.x, other.y, other.width, other.height);
 }
 
 DOMRectReadOnly::DOMRectReadOnly(JS::Realm& realm, double x, double y, double width, double height)
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMRectReadOnly.h b/Userland/Libraries/LibWeb/Geometry/DOMRectReadOnly.h
index 7cc01f8548f..1982ff6f06f 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMRectReadOnly.h
+++ b/Userland/Libraries/LibWeb/Geometry/DOMRectReadOnly.h
@@ -26,7 +26,7 @@ class DOMRectReadOnly : public Bindings::PlatformObject {
 
 public:
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMRectReadOnly>> construct_impl(JS::Realm&, double x = 0, double y = 0, double width = 0, double height = 0);
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMRectReadOnly>> from_rect(JS::VM&, DOMRectInit const&);
+    [[nodiscard]] static JS::NonnullGCPtr<DOMRectReadOnly> from_rect(JS::VM&, DOMRectInit const&);
 
     virtual ~DOMRectReadOnly() override;
 
diff --git a/Userland/Libraries/LibWeb/HTML/AudioTrack.cpp b/Userland/Libraries/LibWeb/HTML/AudioTrack.cpp
index 63d7c534a00..6a972a89a9a 100644
--- a/Userland/Libraries/LibWeb/HTML/AudioTrack.cpp
+++ b/Userland/Libraries/LibWeb/HTML/AudioTrack.cpp
@@ -102,7 +102,7 @@ void AudioTrack::set_enabled(bool enabled)
         // is disabled, the user agent must queue a media element task given the media element to fire an event named
         // change at the AudioTrackList object.
         m_media_element->queue_a_media_element_task([this]() {
-            m_audio_track_list->dispatch_event(DOM::Event::create(realm(), HTML::EventNames::change).release_value_but_fixme_should_propagate_errors());
+            m_audio_track_list->dispatch_event(DOM::Event::create(realm(), HTML::EventNames::change));
         });
     }
 
diff --git a/Userland/Libraries/LibWeb/HTML/BrowsingContext.cpp b/Userland/Libraries/LibWeb/HTML/BrowsingContext.cpp
index ce091da7029..3a83011df35 100644
--- a/Userland/Libraries/LibWeb/HTML/BrowsingContext.cpp
+++ b/Userland/Libraries/LibWeb/HTML/BrowsingContext.cpp
@@ -150,10 +150,10 @@ JS::NonnullGCPtr<BrowsingContext> BrowsingContext::create_a_new_browsing_context
     auto realm_execution_context = Bindings::create_a_new_javascript_realm(
         Bindings::main_thread_vm(),
         [&](JS::Realm& realm) -> JS::Object* {
-            browsing_context->m_window_proxy = realm.heap().allocate<WindowProxy>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+            browsing_context->m_window_proxy = realm.heap().allocate<WindowProxy>(realm, realm);
 
             // - For the global object, create a new Window object.
-            window = HTML::Window::create(realm).release_value_but_fixme_should_propagate_errors();
+            window = HTML::Window::create(realm);
             return window.ptr();
         },
         [&](JS::Realm&) -> JS::Object* {
@@ -173,8 +173,7 @@ JS::NonnullGCPtr<BrowsingContext> BrowsingContext::create_a_new_browsing_context
         move(realm_execution_context),
         {},
         top_level_creation_url,
-        top_level_origin)
-        .release_value_but_fixme_should_propagate_errors();
+        top_level_origin);
 
     // 12. Let loadTimingInfo be a new document load timing info with its navigation start time set to the result of calling
     //     coarsen time with unsafeContextCreationTime and the new environment settings object's cross-origin isolated capability.
@@ -204,7 +203,7 @@ JS::NonnullGCPtr<BrowsingContext> BrowsingContext::create_a_new_browsing_context
     //     load timing info is loadTimingInfo,
     //     FIXME: navigation id is null,
     //     and which is ready for post-load tasks.
-    auto document = HTML::HTMLDocument::create(window->realm()).release_value_but_fixme_should_propagate_errors();
+    auto document = HTML::HTMLDocument::create(window->realm());
 
     // Non-standard
     document->set_window(*window);
@@ -329,10 +328,10 @@ WebIDL::ExceptionOr<BrowsingContext::BrowsingContextAndDocument> BrowsingContext
         Bindings::main_thread_vm(),
         [&](JS::Realm& realm) -> JS::Object* {
             auto window_proxy = realm.heap().allocate<WindowProxy>(realm, realm);
-            browsing_context->set_window_proxy(window_proxy.release_allocated_value_but_fixme_should_propagate_errors());
+            browsing_context->set_window_proxy(window_proxy);
 
             // - For the global object, create a new Window object.
-            window = Window::create(realm).release_value_but_fixme_should_propagate_errors();
+            window = Window::create(realm);
             return window.ptr();
         },
         [&](JS::Realm&) -> JS::Object* {
@@ -347,12 +346,12 @@ WebIDL::ExceptionOr<BrowsingContext::BrowsingContextAndDocument> BrowsingContext
     auto top_level_origin = !embedder ? origin : relevant_settings_object(*embedder).origin();
 
     // 12. Set up a window environment settings object with about:blank, realm execution context, null, topLevelCreationURL, and topLevelOrigin.
-    TRY(WindowEnvironmentSettingsObject::setup(
+    WindowEnvironmentSettingsObject::setup(
         AK::URL("about:blank"),
         move(realm_execution_context),
         {},
         top_level_creation_url,
-        top_level_origin));
+        top_level_origin);
 
     // 13. Let loadTimingInfo be a new document load timing info with its navigation start time set to the result of calling
     //     coarsen time with unsafeContextCreationTime and the new environment settings object's cross-origin isolated capability.
@@ -362,7 +361,7 @@ WebIDL::ExceptionOr<BrowsingContext::BrowsingContextAndDocument> BrowsingContext
         verify_cast<WindowEnvironmentSettingsObject>(Bindings::host_defined_environment_settings_object(window->realm())).cross_origin_isolated_capability() == CanUseCrossOriginIsolatedAPIs::Yes);
 
     // 14. Let document be a new Document, with:
-    auto document = TRY(HTML::HTMLDocument::create(window->realm()));
+    auto document = HTML::HTMLDocument::create(window->realm());
 
     // Non-standard
     document->set_window(*window);
@@ -1435,7 +1434,7 @@ WebIDL::ExceptionOr<void> BrowsingContext::traverse_the_history(size_t entry_ind
             // and the newURL attribute initialized to newURL.
 
             // FIXME: Implement a proper HashChangeEvent class.
-            auto event = DOM::Event::create(verify_cast<HTML::Window>(relevant_global_object(*new_document)).realm(), HTML::EventNames::hashchange).release_value_but_fixme_should_propagate_errors();
+            auto event = DOM::Event::create(verify_cast<HTML::Window>(relevant_global_object(*new_document)).realm(), HTML::EventNames::hashchange);
             new_document->dispatch_event(event);
         });
     }
diff --git a/Userland/Libraries/LibWeb/HTML/CanvasGradient.cpp b/Userland/Libraries/LibWeb/HTML/CanvasGradient.cpp
index 103b02e75b5..a95e8079814 100644
--- a/Userland/Libraries/LibWeb/HTML/CanvasGradient.cpp
+++ b/Userland/Libraries/LibWeb/HTML/CanvasGradient.cpp
@@ -22,21 +22,21 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<CanvasGradient>> CanvasGradient::create_rad
         return WebIDL::IndexSizeError::create(realm, "The r1 passed is less than 0");
 
     auto radial_gradient = TRY_OR_THROW_OOM(realm.vm(), Gfx::CanvasRadialGradientPaintStyle::create(Gfx::FloatPoint { x0, y0 }, r0, Gfx::FloatPoint { x1, y1 }, r1));
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CanvasGradient>(realm, realm, *radial_gradient));
+    return realm.heap().allocate<CanvasGradient>(realm, realm, *radial_gradient);
 }
 
 // https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-createlineargradient
 WebIDL::ExceptionOr<JS::NonnullGCPtr<CanvasGradient>> CanvasGradient::create_linear(JS::Realm& realm, double x0, double y0, double x1, double y1)
 {
     auto linear_gradient = TRY_OR_THROW_OOM(realm.vm(), Gfx::CanvasLinearGradientPaintStyle::create(Gfx::FloatPoint { x0, y0 }, Gfx::FloatPoint { x1, y1 }));
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CanvasGradient>(realm, realm, *linear_gradient));
+    return realm.heap().allocate<CanvasGradient>(realm, realm, *linear_gradient);
 }
 
 // https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-createconicgradient
 WebIDL::ExceptionOr<JS::NonnullGCPtr<CanvasGradient>> CanvasGradient::create_conic(JS::Realm& realm, double start_angle, double x, double y)
 {
     auto conic_gradient = TRY_OR_THROW_OOM(realm.vm(), Gfx::CanvasConicGradientPaintStyle::create(Gfx::FloatPoint { x, y }, start_angle));
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CanvasGradient>(realm, realm, *conic_gradient));
+    return realm.heap().allocate<CanvasGradient>(realm, realm, *conic_gradient);
 }
 
 CanvasGradient::CanvasGradient(JS::Realm& realm, Gfx::GradientPaintStyle& gradient)
diff --git a/Userland/Libraries/LibWeb/HTML/CanvasPattern.cpp b/Userland/Libraries/LibWeb/HTML/CanvasPattern.cpp
index 9c560ac1048..39714b28c3b 100644
--- a/Userland/Libraries/LibWeb/HTML/CanvasPattern.cpp
+++ b/Userland/Libraries/LibWeb/HTML/CanvasPattern.cpp
@@ -130,7 +130,7 @@ WebIDL::ExceptionOr<JS::GCPtr<CanvasPattern>> CanvasPattern::create(JS::Realm& r
     // FIXME: 7. If image is not origin-clean, then mark pattern as not origin-clean.
 
     // 8. Return pattern.
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CanvasPattern>(realm, realm, *pattern));
+    return realm.heap().allocate<CanvasPattern>(realm, realm, *pattern);
 }
 
 void CanvasPattern::initialize(JS::Realm& realm)
diff --git a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
index 07d9ba21832..92d441bc2d4 100644
--- a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
+++ b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
@@ -26,9 +26,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CanvasRenderingContext2D>> CanvasRenderingContext2D::create(JS::Realm& realm, HTMLCanvasElement& element)
+JS::NonnullGCPtr<CanvasRenderingContext2D> CanvasRenderingContext2D::create(JS::Realm& realm, HTMLCanvasElement& element)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CanvasRenderingContext2D>(realm, realm, element));
+    return realm.heap().allocate<CanvasRenderingContext2D>(realm, realm, element);
 }
 
 CanvasRenderingContext2D::CanvasRenderingContext2D(JS::Realm& realm, HTMLCanvasElement& element)
@@ -394,7 +394,7 @@ JS::NonnullGCPtr<TextMetrics> CanvasRenderingContext2D::measure_text(DeprecatedS
     // TextMetrics object with members behaving as described in the following
     // list:
     auto prepared_text = prepare_text(text);
-    auto metrics = TextMetrics::create(realm()).release_value_but_fixme_should_propagate_errors();
+    auto metrics = TextMetrics::create(realm());
     // FIXME: Use the font that was used to create the glyphs in prepared_text.
     auto font = current_font();
 
diff --git a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.h b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.h
index 933a99bbad4..9a99f446e29 100644
--- a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.h
+++ b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.h
@@ -60,7 +60,7 @@ class CanvasRenderingContext2D
     WEB_PLATFORM_OBJECT(CanvasRenderingContext2D, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CanvasRenderingContext2D>> create(JS::Realm&, HTMLCanvasElement&);
+    [[nodiscard]] static JS::NonnullGCPtr<CanvasRenderingContext2D> create(JS::Realm&, HTMLCanvasElement&);
     virtual ~CanvasRenderingContext2D() override;
 
     virtual void fill_rect(float x, float y, float width, float height) override;
diff --git a/Userland/Libraries/LibWeb/HTML/CloseEvent.cpp b/Userland/Libraries/LibWeb/HTML/CloseEvent.cpp
index f941a86b0f7..a839c14f54c 100644
--- a/Userland/Libraries/LibWeb/HTML/CloseEvent.cpp
+++ b/Userland/Libraries/LibWeb/HTML/CloseEvent.cpp
@@ -9,9 +9,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CloseEvent>> CloseEvent::create(JS::Realm& realm, FlyString const& event_name, CloseEventInit const& event_init)
+JS::NonnullGCPtr<CloseEvent> CloseEvent::create(JS::Realm& realm, FlyString const& event_name, CloseEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CloseEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<CloseEvent>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<CloseEvent>> CloseEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, CloseEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/HTML/CloseEvent.h b/Userland/Libraries/LibWeb/HTML/CloseEvent.h
index 95087867175..d73ee045616 100644
--- a/Userland/Libraries/LibWeb/HTML/CloseEvent.h
+++ b/Userland/Libraries/LibWeb/HTML/CloseEvent.h
@@ -22,7 +22,7 @@ class CloseEvent : public DOM::Event {
     WEB_PLATFORM_OBJECT(CloseEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CloseEvent>> create(JS::Realm&, FlyString const& event_name, CloseEventInit const& event_init = {});
+    [[nodiscard]] static JS::NonnullGCPtr<CloseEvent> create(JS::Realm&, FlyString const& event_name, CloseEventInit const& event_init = {});
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<CloseEvent>> construct_impl(JS::Realm&, FlyString const& event_name, CloseEventInit const& event_init);
 
     virtual ~CloseEvent() override;
diff --git a/Userland/Libraries/LibWeb/HTML/CustomElements/CustomElementDefinition.h b/Userland/Libraries/LibWeb/HTML/CustomElements/CustomElementDefinition.h
index ddfd9e7a98c..c12230f555e 100644
--- a/Userland/Libraries/LibWeb/HTML/CustomElements/CustomElementDefinition.h
+++ b/Userland/Libraries/LibWeb/HTML/CustomElements/CustomElementDefinition.h
@@ -24,7 +24,7 @@ class CustomElementDefinition : public JS::Cell {
 
     static JS::NonnullGCPtr<CustomElementDefinition> create(JS::Realm& realm, String const& name, String const& local_name, WebIDL::CallbackType& constructor, Vector<String>&& observed_attributes, LifecycleCallbacksStorage&& lifecycle_callbacks, bool form_associated, bool disable_internals, bool disable_shadow)
     {
-        return realm.heap().allocate<CustomElementDefinition>(realm, name, local_name, constructor, move(observed_attributes), move(lifecycle_callbacks), form_associated, disable_internals, disable_shadow).release_allocated_value_but_fixme_should_propagate_errors();
+        return realm.heap().allocate<CustomElementDefinition>(realm, name, local_name, constructor, move(observed_attributes), move(lifecycle_callbacks), form_associated, disable_internals, disable_shadow);
     }
 
     ~CustomElementDefinition() = default;
diff --git a/Userland/Libraries/LibWeb/HTML/DOMParser.cpp b/Userland/Libraries/LibWeb/HTML/DOMParser.cpp
index 0605ac6318e..9d44da20e70 100644
--- a/Userland/Libraries/LibWeb/HTML/DOMParser.cpp
+++ b/Userland/Libraries/LibWeb/HTML/DOMParser.cpp
@@ -16,7 +16,7 @@ namespace Web::HTML {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMParser>> DOMParser::construct_impl(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<DOMParser>(realm, realm));
+    return realm.heap().allocate<DOMParser>(realm, realm);
 }
 
 DOMParser::DOMParser(JS::Realm& realm)
@@ -42,7 +42,7 @@ JS::NonnullGCPtr<DOM::Document> DOMParser::parse_from_string(DeprecatedString co
     if (type == Bindings::DOMParserSupportedType::Text_Html) {
         // -> "text/html"
         // 1. Set document's type to "html".
-        document = HTML::HTMLDocument::create(realm(), verify_cast<HTML::Window>(relevant_global_object(*this)).associated_document().url()).release_value_but_fixme_should_propagate_errors();
+        document = HTML::HTMLDocument::create(realm(), verify_cast<HTML::Window>(relevant_global_object(*this)).associated_document().url());
         document->set_content_type(Bindings::idl_enum_to_deprecated_string(type));
         document->set_document_type(DOM::Document::Type::HTML);
 
@@ -56,7 +56,7 @@ JS::NonnullGCPtr<DOM::Document> DOMParser::parse_from_string(DeprecatedString co
         parser->run("about:blank"sv);
     } else {
         // -> Otherwise
-        document = DOM::Document::create(realm(), verify_cast<HTML::Window>(relevant_global_object(*this)).associated_document().url()).release_value_but_fixme_should_propagate_errors();
+        document = DOM::Document::create(realm(), verify_cast<HTML::Window>(relevant_global_object(*this)).associated_document().url());
         document->set_content_type(Bindings::idl_enum_to_deprecated_string(type));
 
         // 1. Create an XML parser parse, associated with document, and with XML scripting support disabled.
diff --git a/Userland/Libraries/LibWeb/HTML/DOMStringMap.cpp b/Userland/Libraries/LibWeb/HTML/DOMStringMap.cpp
index c52b9099426..7b3fb7da528 100644
--- a/Userland/Libraries/LibWeb/HTML/DOMStringMap.cpp
+++ b/Userland/Libraries/LibWeb/HTML/DOMStringMap.cpp
@@ -12,10 +12,10 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMStringMap>> DOMStringMap::create(DOM::Element& element)
+JS::NonnullGCPtr<DOMStringMap> DOMStringMap::create(DOM::Element& element)
 {
     auto& realm = element.realm();
-    return MUST_OR_THROW_OOM(realm.heap().allocate<DOMStringMap>(realm, element));
+    return realm.heap().allocate<DOMStringMap>(realm, element);
 }
 
 DOMStringMap::DOMStringMap(DOM::Element& element)
diff --git a/Userland/Libraries/LibWeb/HTML/DOMStringMap.h b/Userland/Libraries/LibWeb/HTML/DOMStringMap.h
index 77f89271f85..ecae5ade8e1 100644
--- a/Userland/Libraries/LibWeb/HTML/DOMStringMap.h
+++ b/Userland/Libraries/LibWeb/HTML/DOMStringMap.h
@@ -17,7 +17,7 @@ class DOMStringMap final : public Bindings::LegacyPlatformObject {
     WEB_PLATFORM_OBJECT(DOMStringMap, Bindings::LegacyPlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMStringMap>> create(DOM::Element&);
+    [[nodiscard]] static JS::NonnullGCPtr<DOMStringMap> create(DOM::Element&);
 
     virtual ~DOMStringMap() override;
 
diff --git a/Userland/Libraries/LibWeb/HTML/ErrorEvent.cpp b/Userland/Libraries/LibWeb/HTML/ErrorEvent.cpp
index b716f86e1fc..bc244491b71 100644
--- a/Userland/Libraries/LibWeb/HTML/ErrorEvent.cpp
+++ b/Userland/Libraries/LibWeb/HTML/ErrorEvent.cpp
@@ -9,9 +9,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<ErrorEvent>> ErrorEvent::create(JS::Realm& realm, FlyString const& event_name, ErrorEventInit const& event_init)
+JS::NonnullGCPtr<ErrorEvent> ErrorEvent::create(JS::Realm& realm, FlyString const& event_name, ErrorEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<ErrorEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<ErrorEvent>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<ErrorEvent>> ErrorEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, ErrorEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/HTML/ErrorEvent.h b/Userland/Libraries/LibWeb/HTML/ErrorEvent.h
index 1c61af2f175..cb4208ed60e 100644
--- a/Userland/Libraries/LibWeb/HTML/ErrorEvent.h
+++ b/Userland/Libraries/LibWeb/HTML/ErrorEvent.h
@@ -25,7 +25,7 @@ class ErrorEvent final : public DOM::Event {
     WEB_PLATFORM_OBJECT(ErrorEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<ErrorEvent>> create(JS::Realm&, FlyString const& event_name, ErrorEventInit const& event_init = {});
+    [[nodiscard]] static JS::NonnullGCPtr<ErrorEvent> create(JS::Realm&, FlyString const& event_name, ErrorEventInit const& = {});
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<ErrorEvent>> construct_impl(JS::Realm&, FlyString const& event_name, ErrorEventInit const& event_init);
 
     virtual ~ErrorEvent() override;
diff --git a/Userland/Libraries/LibWeb/HTML/Focus.cpp b/Userland/Libraries/LibWeb/HTML/Focus.cpp
index 7fef91a1208..23f35e19400 100644
--- a/Userland/Libraries/LibWeb/HTML/Focus.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Focus.cpp
@@ -65,7 +65,7 @@ static void run_focus_update_steps(Vector<JS::Handle<DOM::Node>> old_chain, Vect
         //    with related blur target as the related target.
         if (blur_event_target) {
             // FIXME: Implement the "fire a focus event" spec operation.
-            auto blur_event = UIEvents::FocusEvent::create(blur_event_target->realm(), HTML::EventNames::blur).release_value_but_fixme_should_propagate_errors();
+            auto blur_event = UIEvents::FocusEvent::create(blur_event_target->realm(), HTML::EventNames::blur);
             blur_event->set_related_target(related_blur_target);
             blur_event_target->dispatch_event(blur_event);
         }
@@ -108,7 +108,7 @@ static void run_focus_update_steps(Vector<JS::Handle<DOM::Node>> old_chain, Vect
         //    with related focus target as the related target.
         if (focus_event_target) {
             // FIXME: Implement the "fire a focus event" spec operation.
-            auto focus_event = UIEvents::FocusEvent::create(focus_event_target->realm(), HTML::EventNames::focus).release_value_but_fixme_should_propagate_errors();
+            auto focus_event = UIEvents::FocusEvent::create(focus_event_target->realm(), HTML::EventNames::focus);
             focus_event->set_related_target(related_focus_target);
             focus_event_target->dispatch_event(focus_event);
         }
diff --git a/Userland/Libraries/LibWeb/HTML/FormDataEvent.cpp b/Userland/Libraries/LibWeb/HTML/FormDataEvent.cpp
index a2e243c61dc..8504a4abe5b 100644
--- a/Userland/Libraries/LibWeb/HTML/FormDataEvent.cpp
+++ b/Userland/Libraries/LibWeb/HTML/FormDataEvent.cpp
@@ -12,7 +12,7 @@ namespace Web::HTML {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<FormDataEvent>> FormDataEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, FormDataEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<FormDataEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<FormDataEvent>(realm, realm, event_name, event_init);
 }
 
 FormDataEvent::FormDataEvent(JS::Realm& realm, FlyString const& event_name, FormDataEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLCanvasElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLCanvasElement.cpp
index c7bbf5e9a74..fb2e6e032ef 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLCanvasElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLCanvasElement.cpp
@@ -101,7 +101,7 @@ HTMLCanvasElement::HasOrCreatedContext HTMLCanvasElement::create_2d_context()
     if (!m_context.has<Empty>())
         return m_context.has<JS::NonnullGCPtr<CanvasRenderingContext2D>>() ? HasOrCreatedContext::Yes : HasOrCreatedContext::No;
 
-    m_context = CanvasRenderingContext2D::create(realm(), *this).release_value_but_fixme_should_propagate_errors();
+    m_context = CanvasRenderingContext2D::create(realm(), *this);
     return HasOrCreatedContext::Yes;
 }
 
@@ -266,7 +266,7 @@ WebIDL::ExceptionOr<void> HTMLCanvasElement::to_blob(JS::NonnullGCPtr<WebIDL::Ca
                 // 1. If result is non-null, then set result to a new Blob object, created in the relevant realm of this canvas element, representing result. [FILEAPI]
                 JS::GCPtr<FileAPI::Blob> blob_result;
                 if (file_result.has_value())
-                    blob_result = TRY(FileAPI::Blob::create(realm(), file_result->buffer, TRY_OR_THROW_OOM(vm(), String::from_utf8(file_result->mime_type))));
+                    blob_result = FileAPI::Blob::create(realm(), file_result->buffer, TRY_OR_THROW_OOM(vm(), String::from_utf8(file_result->mime_type)));
 
                 // 2. Invoke callback with « result ».
                 TRY(WebIDL::invoke_callback(*callback, {}, move(blob_result)));
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLDetailsElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLDetailsElement.cpp
index 38d4ecc487b..126b49686e8 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLDetailsElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLDetailsElement.cpp
@@ -48,7 +48,7 @@ void HTMLDetailsElement::run_details_notification_task_steps()
         // 1. FIXME: If another task has been queued to run the details notification task steps for this details element, then return.
 
         // 2. Fire an event named toggle at the details element.
-        dispatch_event(Web::DOM::Event::create(realm(), HTML::EventNames::toggle).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(Web::DOM::Event::create(realm(), HTML::EventNames::toggle));
     });
 }
 
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLDocument.cpp b/Userland/Libraries/LibWeb/HTML/HTMLDocument.cpp
index 4c862a7e83f..76288d2779e 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLDocument.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLDocument.cpp
@@ -20,9 +20,9 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<HTMLDocument>> HTMLDocument::construct_impl
     return HTMLDocument::create(realm);
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<HTMLDocument>> HTMLDocument::create(JS::Realm& realm, AK::URL const& url)
+JS::NonnullGCPtr<HTMLDocument> HTMLDocument::create(JS::Realm& realm, AK::URL const& url)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<HTMLDocument>(realm, realm, url));
+    return realm.heap().allocate<HTMLDocument>(realm, realm, url);
 }
 
 }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLDocument.h b/Userland/Libraries/LibWeb/HTML/HTMLDocument.h
index 45bf05324ed..32d65a3ab46 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLDocument.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLDocument.h
@@ -20,7 +20,7 @@ class HTMLDocument final : public DOM::Document {
 public:
     virtual ~HTMLDocument() override;
 
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<HTMLDocument>> create(JS::Realm&, AK::URL const& url = "about:blank"sv);
+    [[nodiscard]] static JS::NonnullGCPtr<HTMLDocument> create(JS::Realm&, AK::URL const& url = "about:blank"sv);
     WebIDL::ExceptionOr<JS::NonnullGCPtr<HTMLDocument>> construct_impl(JS::Realm&);
 
 private:
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLElement.cpp
index 6bceff7fe38..7ee54e3570d 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLElement.cpp
@@ -48,7 +48,7 @@ void HTMLElement::initialize(JS::Realm& realm)
     Base::initialize(realm);
     set_prototype(&Bindings::ensure_web_prototype<Bindings::HTMLElementPrototype>(realm, "HTMLElement"));
 
-    m_dataset = MUST(DOMStringMap::create(*this));
+    m_dataset = DOMStringMap::create(*this);
 }
 
 void HTMLElement::visit_edges(Cell::Visitor& visitor)
@@ -283,7 +283,7 @@ bool HTMLElement::fire_a_synthetic_pointer_event(FlyString const& type, DOM::Ele
     // 1. Let event be the result of creating an event using PointerEvent.
     // 2. Initialize event's type attribute to e.
     // FIXME: Actually create a PointerEvent!
-    auto event = UIEvents::MouseEvent::create(realm(), type).release_value_but_fixme_should_propagate_errors();
+    auto event = UIEvents::MouseEvent::create(realm(), type);
 
     // 3. Initialize event's bubbles and cancelable attributes to true.
     event->set_bubbles(true);
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp
index 9dbe008fb28..b72ca9446e5 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp
@@ -101,7 +101,7 @@ WebIDL::ExceptionOr<void> HTMLFormElement::submit_form(JS::NonnullGCPtr<HTMLElem
         //    cancelable attribute initialized to true.
         SubmitEventInit event_init {};
         event_init.submitter = submitter_button;
-        auto submit_event = SubmitEvent::create(realm, EventNames::submit, event_init).release_value_but_fixme_should_propagate_errors();
+        auto submit_event = SubmitEvent::create(realm, EventNames::submit, event_init);
         submit_event->set_bubbles(true);
         submit_event->set_cancelable(true);
         bool should_continue = dispatch_event(*submit_event);
@@ -258,7 +258,7 @@ WebIDL::ExceptionOr<void> HTMLFormElement::submit_form(JS::NonnullGCPtr<HTMLElem
 void HTMLFormElement::reset_form()
 {
     // 1. Let reset be the result of firing an event named reset at form, with the bubbles and cancelable attributes initialized to true.
-    auto reset_event = DOM::Event::create(realm(), HTML::EventNames::reset).release_value_but_fixme_should_propagate_errors();
+    auto reset_event = DOM::Event::create(realm(), HTML::EventNames::reset);
     reset_event->set_bubbles(true);
     reset_event->set_cancelable(true);
 
@@ -411,7 +411,7 @@ JS::NonnullGCPtr<DOM::HTMLCollection> HTMLFormElement::elements() const
     if (!m_elements) {
         m_elements = DOM::HTMLCollection::create(const_cast<HTMLFormElement&>(*this), DOM::HTMLCollection::Scope::Descendants, [](Element const& element) {
             return is_form_control(element);
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_elements;
 }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLIFrameElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLIFrameElement.cpp
index 715df6d5423..63a50239688 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLIFrameElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLIFrameElement.cpp
@@ -163,7 +163,7 @@ void run_iframe_load_event_steps(HTML::HTMLIFrameElement& element)
     // FIXME: 4. Set childDocument's iframe load in progress flag.
 
     // 5. Fire an event named load at element.
-    element.dispatch_event(DOM::Event::create(element.realm(), HTML::EventNames::load).release_value_but_fixme_should_propagate_errors());
+    element.dispatch_event(DOM::Event::create(element.realm(), HTML::EventNames::load));
 
     // FIXME: 6. Unset childDocument's iframe load in progress flag.
 }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLImageElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLImageElement.cpp
index c1963dd89c1..ab116b07e7a 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLImageElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLImageElement.cpp
@@ -391,7 +391,7 @@ ErrorOr<void> HTMLImageElement::update_the_image_data(bool restart_animations, b
 
                 // 3. If maybe omit events is not set or previousURL is not equal to urlString, then fire an event named load at the img element.
                 if (!maybe_omit_events || previous_url != url_string)
-                    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::load).release_value_but_fixme_should_propagate_errors());
+                    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::load));
             });
 
             // 8. Abort the update the image data algorithm.
@@ -434,7 +434,7 @@ after_step_7:
                 if (
                     (has_attribute(HTML::AttributeNames::src) || uses_srcset_or_picture())
                     && (!maybe_omit_events || m_current_request->current_url() != ""sv)) {
-                    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+                    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error));
                 }
             });
 
@@ -463,7 +463,7 @@ after_step_7:
 
                 // 2. If maybe omit events is not set or previousURL is not equal to selected source, then fire an event named error at the img element.
                 if (!maybe_omit_events || previous_url != selected_source.value().url)
-                    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+                    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error));
             });
 
             // 5. Return.
@@ -585,7 +585,7 @@ void HTMLImageElement::add_callbacks_to_image_request(NonnullRefPtr<ImageRequest
 
                 // 4. If maybe omit events is not set or previousURL is not equal to urlString, then fire an event named load at the img element.
                 if (!maybe_omit_events || previous_url != url_string)
-                    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::load).release_value_but_fixme_should_propagate_errors());
+                    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::load));
 
                 set_needs_style_update(true);
                 document().set_needs_layout();
@@ -617,7 +617,7 @@ void HTMLImageElement::add_callbacks_to_image_request(NonnullRefPtr<ImageRequest
             // queue an element task on the DOM manipulation task source given the img element
             // to fire an event named error at the img element.
             if (!maybe_omit_events || previous_url != url_string)
-                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error));
 
             m_load_event_delayer.clear();
         });
@@ -726,7 +726,7 @@ void HTMLImageElement::react_to_changes_in_the_environment()
             document().set_needs_layout();
 
             // 7. Fire an event named load at the img element.
-            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::load).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::load));
         });
     };
 
@@ -803,7 +803,7 @@ void HTMLImageElement::upgrade_pending_request_to_current_request()
 void HTMLImageElement::handle_failed_fetch()
 {
     // AD-HOC
-    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error));
 }
 
 // https://html.spec.whatwg.org/multipage/rendering.html#restart-the-animation
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.cpp
index ce0a9422b2a..8683ccfba0f 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.cpp
@@ -135,7 +135,7 @@ JS::GCPtr<FileAPI::FileList> HTMLInputElement::files()
         return nullptr;
 
     if (!m_selected_files)
-        m_selected_files = FileAPI::FileList::create(realm(), {}).release_value_but_fixme_should_propagate_errors();
+        m_selected_files = FileAPI::FileList::create(realm(), {});
     return m_selected_files;
 }
 
@@ -159,11 +159,11 @@ void HTMLInputElement::update_the_file_selection(JS::NonnullGCPtr<FileAPI::FileL
         this->set_files(files.ptr());
 
         // 2. Fire an event named input at the input element, with the bubbles and composed attributes initialized to true.
-        auto input_event = DOM::Event::create(this->realm(), EventNames::input, { .bubbles = true, .composed = true }).release_value_but_fixme_should_propagate_errors();
+        auto input_event = DOM::Event::create(this->realm(), EventNames::input, { .bubbles = true, .composed = true });
         this->dispatch_event(input_event);
 
         // 3. Fire an event named change at the input element, with the bubbles attribute initialized to true.
-        auto change_event = DOM::Event::create(this->realm(), EventNames::change, { .bubbles = true }).release_value_but_fixme_should_propagate_errors();
+        auto change_event = DOM::Event::create(this->realm(), EventNames::change, { .bubbles = true });
         this->dispatch_event(change_event);
     });
 }
@@ -250,13 +250,13 @@ WebIDL::ExceptionOr<void> HTMLInputElement::run_input_activation_behavior()
             return {};
 
         // 2. Fire an event named input at the element with the bubbles and composed attributes initialized to true.
-        auto input_event = DOM::Event::create(realm(), HTML::EventNames::input).release_value_but_fixme_should_propagate_errors();
+        auto input_event = DOM::Event::create(realm(), HTML::EventNames::input);
         input_event->set_bubbles(true);
         input_event->set_composed(true);
         dispatch_event(input_event);
 
         // 3. Fire an event named change at the element with the bubbles attribute initialized to true.
-        auto change_event = DOM::Event::create(realm(), HTML::EventNames::change).release_value_but_fixme_should_propagate_errors();
+        auto change_event = DOM::Event::create(realm(), HTML::EventNames::change);
         change_event->set_bubbles(true);
         dispatch_event(*change_event);
     } else if (type_state() == TypeAttributeState::SubmitButton) {
@@ -274,7 +274,7 @@ WebIDL::ExceptionOr<void> HTMLInputElement::run_input_activation_behavior()
     } else if (type_state() == TypeAttributeState::FileUpload) {
         show_the_picker_if_applicable(*this);
     } else {
-        dispatch_event(DOM::Event::create(realm(), EventNames::change).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(DOM::Event::create(realm(), EventNames::change));
     }
 
     return {};
@@ -291,7 +291,7 @@ void HTMLInputElement::did_edit_text_node(Badge<BrowsingContext>)
     // NOTE: This is a bit ad-hoc, but basically implements part of "4.10.5.5 Common event behaviors"
     //       https://html.spec.whatwg.org/multipage/input.html#common-input-element-events
     queue_an_element_task(HTML::Task::Source::UserInteraction, [this] {
-        auto input_event = DOM::Event::create(realm(), HTML::EventNames::input).release_value_but_fixme_should_propagate_errors();
+        auto input_event = DOM::Event::create(realm(), HTML::EventNames::input);
         input_event->set_bubbles(true);
         input_event->set_composed(true);
         dispatch_event(*input_event);
@@ -431,7 +431,7 @@ void HTMLInputElement::create_shadow_tree_if_needed()
         break;
     }
 
-    auto shadow_root = heap().allocate<DOM::ShadowRoot>(realm(), document(), *this, Bindings::ShadowRootMode::Closed).release_allocated_value_but_fixme_should_propagate_errors();
+    auto shadow_root = heap().allocate<DOM::ShadowRoot>(realm(), document(), *this, Bindings::ShadowRootMode::Closed);
     auto initial_value = m_value;
     if (initial_value.is_null())
         initial_value = DeprecatedString::empty();
@@ -445,10 +445,10 @@ void HTMLInputElement::create_shadow_tree_if_needed()
         padding: 1px 2px;
 )~~~"));
 
-    m_placeholder_element = heap().allocate<PlaceholderElement>(realm(), document()).release_allocated_value_but_fixme_should_propagate_errors();
+    m_placeholder_element = heap().allocate<PlaceholderElement>(realm(), document());
     MUST(m_placeholder_element->style_for_bindings()->set_property(CSS::PropertyID::Height, "1lh"sv));
 
-    m_placeholder_text_node = heap().allocate<DOM::Text>(realm(), document(), initial_value).release_allocated_value_but_fixme_should_propagate_errors();
+    m_placeholder_text_node = heap().allocate<DOM::Text>(realm(), document(), initial_value);
     m_placeholder_text_node->set_data(attribute(HTML::AttributeNames::placeholder));
     m_placeholder_text_node->set_owner_input_element({}, *this);
     MUST(m_placeholder_element->append_child(*m_placeholder_text_node));
@@ -457,7 +457,7 @@ void HTMLInputElement::create_shadow_tree_if_needed()
     m_inner_text_element = DOM::create_element(document(), HTML::TagNames::div, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
     MUST(m_inner_text_element->style_for_bindings()->set_property(CSS::PropertyID::Height, "1lh"sv));
 
-    m_text_node = heap().allocate<DOM::Text>(realm(), document(), initial_value).release_allocated_value_but_fixme_should_propagate_errors();
+    m_text_node = heap().allocate<DOM::Text>(realm(), document(), initial_value);
     m_text_node->set_always_editable(m_type != TypeAttributeState::FileUpload);
     m_text_node->set_owner_input_element({}, *this);
 
@@ -485,7 +485,7 @@ void HTMLInputElement::did_lose_focus()
     // The change event fires when the value is committed, if that makes sense for the control,
     // or else when the control loses focus
     queue_an_element_task(HTML::Task::Source::UserInteraction, [this] {
-        auto change_event = DOM::Event::create(realm(), HTML::EventNames::change).release_value_but_fixme_should_propagate_errors();
+        auto change_event = DOM::Event::create(realm(), HTML::EventNames::change);
         change_event->set_bubbles(true);
         dispatch_event(change_event);
     });
@@ -842,7 +842,7 @@ void HTMLInputElement::reset_algorithm()
     m_checked = has_attribute(AttributeNames::checked);
 
     // empty the list of selected files,
-    m_selected_files = FileAPI::FileList::create(realm(), {}).release_value_but_fixme_should_propagate_errors();
+    m_selected_files = FileAPI::FileList::create(realm(), {});
 
     // and then invoke the value sanitization algorithm, if the type attribute's current state defines one.
     m_value = value_sanitization_algorithm(m_value);
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLLinkElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLLinkElement.cpp
index 1e4a6ee33ef..e15182e0729 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLLinkElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLLinkElement.cpp
@@ -133,7 +133,7 @@ void HTMLLinkElement::resource_did_fail()
 {
     dbgln_if(CSS_LOADER_DEBUG, "HTMLLinkElement: Resource did fail. URL: {}", resource()->url());
     if (m_relationship & Relationship::Preload) {
-        dispatch_event(*DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(*DOM::Event::create(realm(), HTML::EventNames::error));
     }
 }
 
@@ -145,7 +145,7 @@ void HTMLLinkElement::resource_did_load()
         m_document_load_event_delayer.clear();
     }
     if (m_relationship & Relationship::Preload) {
-        dispatch_event(*DOM::Event::create(realm(), HTML::EventNames::load).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(*DOM::Event::create(realm(), HTML::EventNames::load));
     }
 }
 
@@ -353,13 +353,13 @@ void HTMLLinkElement::process_stylesheet_resource(bool success, Fetch::Infrastru
         if (!decoder.has_value()) {
             // If we don't support the encoding yet, let's error out instead of trying to decode it as something it's most likely not.
             dbgln("FIXME: Style sheet encoding '{}' is not supported yet", encoding);
-            dispatch_event(*DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(*DOM::Event::create(realm(), HTML::EventNames::error));
         } else {
             auto const& encoded_string = body_bytes.get<ByteBuffer>();
             auto maybe_decoded_string = TextCodec::convert_input_to_utf8_using_given_decoder_unless_there_is_a_byte_order_mark(*decoder, encoded_string);
             if (maybe_decoded_string.is_error()) {
                 dbgln("Style sheet {} claimed to be '{}' but decoding failed", response.url().value_or(AK::URL()), encoding);
-                dispatch_event(*DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(*DOM::Event::create(realm(), HTML::EventNames::error));
             } else {
                 auto const decoded_string = maybe_decoded_string.release_value();
                 m_loaded_style_sheet = parse_css_stylesheet(CSS::Parser::ParsingContext(document(), *response.url()), decoded_string);
@@ -373,13 +373,13 @@ void HTMLLinkElement::process_stylesheet_resource(bool success, Fetch::Infrastru
                 }
 
                 // 2. Fire an event named load at el.
-                dispatch_event(*DOM::Event::create(realm(), HTML::EventNames::load).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(*DOM::Event::create(realm(), HTML::EventNames::load));
             }
         }
     }
     // 5. Otherwise, fire an event named error at el.
     else {
-        dispatch_event(*DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(*DOM::Event::create(realm(), HTML::EventNames::error));
     }
 
     // FIXME: 6. If el contributes a script-blocking style sheet, then:
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp
index dd381177e4a..544ce46fce9 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp
@@ -52,9 +52,9 @@ void HTMLMediaElement::initialize(JS::Realm& realm)
     Base::initialize(realm);
     set_prototype(&Bindings::ensure_web_prototype<Bindings::HTMLMediaElementPrototype>(realm, "HTMLMediaElement"));
 
-    m_audio_tracks = MUST(realm.heap().allocate<AudioTrackList>(realm, realm));
-    m_video_tracks = MUST(realm.heap().allocate<VideoTrackList>(realm, realm));
-    m_document_observer = MUST(realm.heap().allocate<DOM::DocumentObserver>(realm, realm, document()));
+    m_audio_tracks = realm.heap().allocate<AudioTrackList>(realm, realm);
+    m_video_tracks = realm.heap().allocate<VideoTrackList>(realm, realm);
+    m_document_observer = realm.heap().allocate<DOM::DocumentObserver>(realm, realm, document());
 
     // https://html.spec.whatwg.org/multipage/media.html#playing-the-media-resource:media-element-82
     m_document_observer->document_became_inactive = [this]() {
@@ -136,7 +136,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::set_decoder_error(String error_messa
         m_fetch_controller->stop_fetch();
 
     // 2. Set the error attribute to the result of creating a MediaError with MEDIA_ERR_DECODE.
-    m_error = TRY(vm.heap().allocate<MediaError>(realm, realm, MediaError::Code::Decode, move(error_message)));
+    m_error = vm.heap().allocate<MediaError>(realm, realm, MediaError::Code::Decode, move(error_message));
 
     // 3. Set the element's networkState attribute to the NETWORK_IDLE value.
     m_network_state = NetworkState::Idle;
@@ -145,7 +145,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::set_decoder_error(String error_messa
     m_delaying_the_load_event.clear();
 
     // 5. Fire an event named error at the media element.
-    dispatch_event(TRY(DOM::Event::create(realm, HTML::EventNames::error)));
+    dispatch_event(DOM::Event::create(realm, HTML::EventNames::error));
 
     // FIXME: 6. Abort the overall resource selection algorithm.
 
@@ -153,7 +153,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::set_decoder_error(String error_messa
 }
 
 // https://html.spec.whatwg.org/multipage/media.html#dom-media-buffered
-WebIDL::ExceptionOr<JS::NonnullGCPtr<TimeRanges>> HTMLMediaElement::buffered() const
+JS::NonnullGCPtr<TimeRanges> HTMLMediaElement::buffered() const
 {
     auto& realm = this->realm();
     auto& vm = realm.vm();
@@ -162,7 +162,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<TimeRanges>> HTMLMediaElement::buffered() c
     //        media resource, if any, that the user agent has buffered, at the time the attribute is evaluated. Users agents
     //        must accurately determine the ranges available, even for media streams where this can only be determined by
     //        tedious inspection.
-    return TRY(vm.heap().allocate<TimeRanges>(realm, realm));
+    return vm.heap().allocate<TimeRanges>(realm, realm);
 }
 
 // https://html.spec.whatwg.org/multipage/media.html#dom-navigator-canplaytype
@@ -286,7 +286,7 @@ void HTMLMediaElement::set_current_playback_position(double playback_position)
     // NOTE: Invoking the following steps is not listed in the spec. Rather, the spec just describes the scenario in
     //       which these steps should be invoked, which is when we've reached the end of the media playback.
     if (m_current_playback_position == m_duration)
-        reached_end_of_media_playback().release_value_but_fixme_should_propagate_errors();
+        reached_end_of_media_playback();
 }
 
 // https://html.spec.whatwg.org/multipage/media.html#dom-media-duration
@@ -319,7 +319,7 @@ void HTMLMediaElement::set_duration(double duration)
     // ends up being greater than the time of the end of the media resource, then the user agent must also seek to the time of the end of the media resource.
     if (!isnan(duration)) {
         queue_a_media_element_task([this] {
-            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::durationchange).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::durationchange));
         });
 
         if (m_current_playback_position > duration)
@@ -422,7 +422,7 @@ void HTMLMediaElement::volume_or_muted_attribute_changed()
     // agent must queue a media element task given the media element to fire an event named volumechange at the media
     // element.
     queue_a_media_element_task([this] {
-        dispatch_event(DOM::Event::create(realm(), HTML::EventNames::volumechange).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(DOM::Event::create(realm(), HTML::EventNames::volumechange));
     });
 
     // FIXME: Then, if the media element is not allowed to play, the user agent must run the internal pause steps for the media element.
@@ -477,7 +477,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::load_element()
     //    fire an event named abort at the media element.
     if (m_network_state == NetworkState::Loading || m_network_state == NetworkState::Idle) {
         queue_a_media_element_task([this] {
-            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::abort).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::abort));
         });
     }
 
@@ -485,7 +485,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::load_element()
     if (m_network_state != NetworkState::Empty) {
         // 1. Queue a media element task given the media element to fire an event named emptied at the media element.
         queue_a_media_element_task([this] {
-            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::emptied).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::emptied));
         });
 
         // 2. If a fetching process is in progress for the media element, the user agent should stop it.
@@ -525,7 +525,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::load_element()
             // If this changed the official playback position, then queue a media element task given the media element to fire an
             // event named timeupdate at the media element.
             queue_a_media_element_task([this] {
-                dispatch_time_update_event().release_value_but_fixme_should_propagate_errors();
+                dispatch_time_update_event();
             });
         }
 
@@ -632,7 +632,7 @@ private:
     {
         // 9. Failed with elements: Queue a media element task given the media element to fire an event named error at candidate.
         m_media_element->queue_a_media_element_task([this]() {
-            m_candidate->dispatch_event(DOM::Event::create(m_candidate->realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+            m_candidate->dispatch_event(DOM::Event::create(m_candidate->realm(), HTML::EventNames::error));
         });
 
         // FIXME: 10. Await a stable state. The synchronous section consists of all the remaining steps of this algorithm until
@@ -788,7 +788,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::select_resource()
 
     // 8. ⌛ Queue a media element task given the media element to fire an event named loadstart at the media element.
     queue_a_media_element_task([this] {
-        dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::loadstart).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::loadstart));
     });
 
     // 9. Run the appropriate steps from the following list:
@@ -878,7 +878,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::select_resource()
         // NOTE: We do not bother with maintaining this pointer. We inspect the DOM tree on the fly, rather than dealing
         //       with the headache of auto-updating this pointer as the DOM changes.
 
-        m_source_element_selector = TRY(vm.heap().allocate<SourceElementSelector>(realm, *this, *candidate));
+        m_source_element_selector = vm.heap().allocate<SourceElementSelector>(realm, *this, *candidate);
         TRY(m_source_element_selector->process_candidate());
 
         break;
@@ -1081,7 +1081,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::process_media_data(Function<void(Str
     // -> If the media resource is found to have an audio track
     if (!audio_loader.is_error()) {
         // 1. Create an AudioTrack object to represent the audio track.
-        audio_track = TRY(vm.heap().allocate<AudioTrack>(realm, realm, *this, audio_loader.release_value()));
+        audio_track = vm.heap().allocate<AudioTrack>(realm, realm, *this, audio_loader.release_value());
 
         // 2. Update the media element's audioTracks attribute's AudioTrackList object with the new AudioTrack object.
         TRY_OR_THROW_OOM(vm, m_audio_tracks->add_track({}, *audio_track));
@@ -1106,14 +1106,14 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::process_media_data(Function<void(Str
         TrackEventInit event_init {};
         event_init.track = JS::make_handle(audio_track);
 
-        auto event = TRY(TrackEvent::create(realm, HTML::EventNames::addtrack, move(event_init)));
+        auto event = TrackEvent::create(realm, HTML::EventNames::addtrack, move(event_init));
         m_audio_tracks->dispatch_event(event);
     }
 
     // -> If the media resource is found to have a video track
     if (!playback_manager.is_error()) {
         // 1. Create a VideoTrack object to represent the video track.
-        video_track = TRY(vm.heap().allocate<VideoTrack>(realm, realm, *this, playback_manager.release_value()));
+        video_track = vm.heap().allocate<VideoTrack>(realm, realm, *this, playback_manager.release_value());
 
         // 2. Update the media element's videoTracks attribute's VideoTrackList object with the new VideoTrack object.
         TRY_OR_THROW_OOM(vm, m_video_tracks->add_track({}, *video_track));
@@ -1139,7 +1139,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::process_media_data(Function<void(Str
         TrackEventInit event_init {};
         event_init.track = JS::make_handle(video_track);
 
-        auto event = TRY(TrackEvent::create(realm, HTML::EventNames::addtrack, move(event_init)));
+        auto event = TrackEvent::create(realm, HTML::EventNames::addtrack, move(event_init));
         m_video_tracks->dispatch_event(event);
     }
 
@@ -1170,7 +1170,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::process_media_data(Function<void(Str
             video_element.set_video_height(video_track->pixel_height());
 
             queue_a_media_element_task([this] {
-                dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::resize).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::resize));
             });
         } else {
             auto duration = audio_track ? audio_track->duration() : video_track->duration();
@@ -1208,11 +1208,11 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::process_media_data(Function<void(Str
     // -> Once the entire media resource has been fetched (but potentially before any of it has been decoded)
     if (audio_track != nullptr || video_track != nullptr) {
         // Fire an event named progress at the media element.
-        dispatch_event(TRY(DOM::Event::create(this->realm(), HTML::EventNames::progress)));
+        dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::progress));
 
         // Set the networkState to NETWORK_IDLE and fire an event named suspend at the media element.
         m_network_state = NetworkState::Idle;
-        dispatch_event(TRY(DOM::Event::create(this->realm(), HTML::EventNames::suspend)));
+        dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::suspend));
 
         // If the user agent ever discards any media data and then needs to resume the network activity to obtain it again, then it must queue a media
         // element task given the media element to set the networkState to NETWORK_LOADING.
@@ -1234,7 +1234,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::handle_media_source_failure(Span<JS:
     auto& vm = realm.vm();
 
     // 1. Set the error attribute to the result of creating a MediaError with MEDIA_ERR_SRC_NOT_SUPPORTED.
-    m_error = TRY(vm.heap().allocate<MediaError>(realm, realm, MediaError::Code::SrcNotSupported, move(error_message)));
+    m_error = vm.heap().allocate<MediaError>(realm, realm, MediaError::Code::SrcNotSupported, move(error_message));
 
     // 2. Forget the media element's media-resource-specific tracks.
     forget_media_resource_specific_tracks();
@@ -1246,7 +1246,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::handle_media_source_failure(Span<JS:
     set_show_poster(true);
 
     // 5. Fire an event named error at the media element.
-    dispatch_event(TRY(DOM::Event::create(realm, HTML::EventNames::error)));
+    dispatch_event(DOM::Event::create(realm, HTML::EventNames::error));
 
     // 6. Reject pending play promises with promises and a "NotSupportedError" DOMException.
     reject_pending_play_promises<WebIDL::NotSupportedError>(promises, "Media is not supported"_fly_string);
@@ -1286,7 +1286,7 @@ void HTMLMediaElement::set_ready_state(ReadyState ready_state)
     if (m_ready_state == ReadyState::HaveNothing && ready_state == ReadyState::HaveMetadata) {
         // Queue a media element task given the media element to fire an event named loadedmetadata at the element.
         queue_a_media_element_task([this] {
-            dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::loadedmetadata).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::loadedmetadata));
         });
 
         return;
@@ -1300,7 +1300,7 @@ void HTMLMediaElement::set_ready_state(ReadyState ready_state)
             m_first_data_load_event_since_load_start = false;
 
             queue_a_media_element_task([this] {
-                dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::loadeddata).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::loadeddata));
             });
         }
 
@@ -1327,7 +1327,7 @@ void HTMLMediaElement::set_ready_state(ReadyState ready_state)
     if (m_ready_state <= ReadyState::HaveCurrentData && ready_state == ReadyState::HaveFutureData) {
         // The user agent must queue a media element task given the media element to fire an event named canplay at the element.
         queue_a_media_element_task([this] {
-            dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::canplay).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::canplay));
         });
 
         // If the element's paused attribute is false, the user agent must notify about playing for the element.
@@ -1343,7 +1343,7 @@ void HTMLMediaElement::set_ready_state(ReadyState ready_state)
         // named canplay at the element, and, if the element's paused attribute is false, notify about playing for the element.
         if (m_ready_state <= ReadyState::HaveCurrentData) {
             queue_a_media_element_task([this] {
-                dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::canplay).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::canplay));
             });
 
             if (!paused())
@@ -1352,7 +1352,7 @@ void HTMLMediaElement::set_ready_state(ReadyState ready_state)
 
         // The user agent must queue a media element task given the media element to fire an event named canplaythrough at the element.
         queue_a_media_element_task([this] {
-            dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::canplaythrough).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(DOM::Event::create(this->realm(), HTML::EventNames::canplaythrough));
         });
 
         // If the element is not eligible for autoplay, then the user agent must abort these substeps.
@@ -1372,7 +1372,7 @@ void HTMLMediaElement::set_ready_state(ReadyState ready_state)
 
             // Queue a media element task given the element to fire an event named play at the element.
             queue_a_media_element_task([this]() {
-                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::play).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::play));
             });
 
             // Notify about playing for the element.
@@ -1416,14 +1416,14 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::play_element()
 
         // 3. Queue a media element task given the media element to fire an event named play at the element.
         queue_a_media_element_task([this]() {
-            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::play).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::play));
         });
 
         // 4. If the media element's readyState attribute has the value HAVE_NOTHING, HAVE_METADATA, or HAVE_CURRENT_DATA,
         //    queue a media element task given the media element to fire an event named waiting at the element.
         if (m_ready_state == ReadyState::HaveNothing || m_ready_state == ReadyState::HaveMetadata || m_ready_state == ReadyState::HaveCurrentData) {
             queue_a_media_element_task([this]() {
-                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::waiting).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::waiting));
             });
         }
         //    Otherwise, the media element's readyState attribute has the value HAVE_FUTURE_DATA or HAVE_ENOUGH_DATA:
@@ -1469,10 +1469,10 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::pause_element()
             auto& realm = this->realm();
 
             // 1. Fire an event named timeupdate at the element.
-            dispatch_time_update_event().release_value_but_fixme_should_propagate_errors();
+            dispatch_time_update_event();
 
             // 2. Fire an event named pause at the element.
-            dispatch_event(DOM::Event::create(realm, HTML::EventNames::pause).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(DOM::Event::create(realm, HTML::EventNames::pause));
 
             // 3. Reject pending play promises with promises and an "AbortError" DOMException.
             reject_pending_play_promises<WebIDL::AbortError>(promises, "Media playback was paused"_fly_string);
@@ -1529,7 +1529,7 @@ void HTMLMediaElement::seek_element(double playback_position, MediaSeekMode seek
 
     // 10. Queue a media element task given the media element to fire an event named seeking at the element.
     queue_a_media_element_task([this]() {
-        dispatch_event(DOM::Event::create(realm(), HTML::EventNames::seeking).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(DOM::Event::create(realm(), HTML::EventNames::seeking));
     });
 
     // 11. Set the current playback position to the new playback position.
@@ -1552,12 +1552,12 @@ void HTMLMediaElement::seek_element(double playback_position, MediaSeekMode seek
 
     // 16. ⌛ Queue a media element task given the media element to fire an event named timeupdate at the element.
     queue_a_media_element_task([this]() {
-        dispatch_time_update_event().release_value_but_fixme_should_propagate_errors();
+        dispatch_time_update_event();
     });
 
     // 17. ⌛ Queue a media element task given the media element to fire an event named seeked at the element.
     queue_a_media_element_task([this]() {
-        dispatch_event(DOM::Event::create(realm(), HTML::EventNames::seeked).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(DOM::Event::create(realm(), HTML::EventNames::seeked));
     });
 }
 
@@ -1570,7 +1570,7 @@ void HTMLMediaElement::notify_about_playing()
     // 2. Queue a media element task given the element and the following steps:
     queue_a_media_element_task([this, promises = move(promises)]() {
         // 1. Fire an event named playing at the element.
-        dispatch_event(DOM::Event::create(realm(), HTML::EventNames::playing).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(DOM::Event::create(realm(), HTML::EventNames::playing));
 
         // 2. Resolve pending play promises with promises.
         resolve_pending_play_promises(promises);
@@ -1690,7 +1690,7 @@ bool HTMLMediaElement::has_ended_playback() const
 }
 
 // https://html.spec.whatwg.org/multipage/media.html#reaches-the-end
-WebIDL::ExceptionOr<void> HTMLMediaElement::reached_end_of_media_playback()
+void HTMLMediaElement::reached_end_of_media_playback()
 {
     // 1. If the media element has a loop attribute specified, then seek to the earliest possible position of the media resource and return.
     if (has_attribute(HTML::AttributeNames::loop)) {
@@ -1700,8 +1700,6 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::reached_end_of_media_playback()
         //         playing manually to actually loop. Note that we don't need to update any HTMLMediaElement state as
         //         it hasn't left the playing state by this point.
         on_playing();
-
-        return {};
     }
 
     // 2. As defined above, the ended IDL attribute starts returning true once the event loop returns to step 1.
@@ -1709,7 +1707,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::reached_end_of_media_playback()
     // 3. Queue a media element task given the media element and the following steps:
     queue_a_media_element_task([this]() mutable {
         // 1. Fire an event named timeupdate at the media element.
-        dispatch_time_update_event().release_value_but_fixme_should_propagate_errors();
+        dispatch_time_update_event();
 
         // 2. If the media element has ended playback, the direction of playback is forwards, and paused is false, then:
         // FIXME: Detect playback direction.
@@ -1718,7 +1716,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::reached_end_of_media_playback()
             set_paused(true);
 
             // 2. Fire an event named pause at the media element.
-            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::pause).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::pause));
 
             // 3. Take pending play promises and reject pending play promises with the result and an "AbortError" DOMException.
             auto promises = take_pending_play_promises();
@@ -1727,20 +1725,17 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::reached_end_of_media_playback()
     });
 
     // 4. Fire an event named ended at the media element.
-    dispatch_event(TRY(DOM::Event::create(realm(), HTML::EventNames::ended)));
-
-    return {};
+    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::ended));
 }
 
-WebIDL::ExceptionOr<void> HTMLMediaElement::dispatch_time_update_event()
+void HTMLMediaElement::dispatch_time_update_event()
 {
     ScopeGuard guard { [this] { m_running_time_update_event_handler = false; } };
     m_running_time_update_event_handler = true;
 
     m_last_time_update_event_time = MonotonicTime::now();
 
-    dispatch_event(TRY(DOM::Event::create(realm(), HTML::EventNames::timeupdate)));
-    return {};
+    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::timeupdate));
 }
 
 // https://html.spec.whatwg.org/multipage/media.html#time-marches-on
@@ -1775,7 +1770,7 @@ void HTMLMediaElement::time_marches_on(TimeMarchesOnReason reason)
 
         if (dispatch_event) {
             queue_a_media_element_task([this]() {
-                dispatch_time_update_event().release_value_but_fixme_should_propagate_errors();
+                dispatch_time_update_event();
             });
         }
     }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.h b/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.h
index 854238a6387..21246c2e84b 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.h
@@ -56,7 +56,7 @@ public:
     };
     NetworkState network_state() const { return m_network_state; }
 
-    WebIDL::ExceptionOr<JS::NonnullGCPtr<TimeRanges>> buffered() const;
+    [[nodiscard]] JS::NonnullGCPtr<TimeRanges> buffered() const;
 
     WebIDL::ExceptionOr<Bindings::CanPlayTypeResult> can_play_type(DeprecatedString const& type) const;
 
@@ -177,9 +177,9 @@ private:
 
     bool is_eligible_for_autoplay() const;
     bool has_ended_playback() const;
-    WebIDL::ExceptionOr<void> reached_end_of_media_playback();
+    void reached_end_of_media_playback();
 
-    WebIDL::ExceptionOr<void> dispatch_time_update_event();
+    void dispatch_time_update_event();
 
     enum class TimeMarchesOnReason {
         NormalPlayback,
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLObjectElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLObjectElement.cpp
index 7e7186a1e2c..c7eecea8a5b 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLObjectElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLObjectElement.cpp
@@ -125,7 +125,7 @@ void HTMLObjectElement::queue_element_task_to_run_object_representation_steps()
 
             // 3. If that failed, fire an event named error at the element, then jump to the step below labeled fallback.
             if (!url.is_valid()) {
-                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error));
                 return run_object_representation_fallback_steps();
             }
 
@@ -152,7 +152,7 @@ void HTMLObjectElement::queue_element_task_to_run_object_representation_steps()
 void HTMLObjectElement::resource_did_fail()
 {
     // 4.7. If the load failed (e.g. there was an HTTP 404 error, there was a DNS error), fire an event named error at the element, then jump to the step below labeled fallback.
-    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error));
     run_object_representation_fallback_steps();
 }
 
@@ -290,7 +290,7 @@ void HTMLObjectElement::run_object_representation_completed_steps(Representation
     // 4.11. If the object element does not represent its nested browsing context, then once the resource is completely loaded, queue an element task on the DOM manipulation task source given the object element to fire an event named load at the element.
     if (representation != Representation::NestedBrowsingContext) {
         queue_an_element_task(HTML::Task::Source::DOMManipulation, [&]() {
-            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::load).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(DOM::Event::create(realm(), HTML::EventNames::load));
         });
     }
 
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLOptionsCollection.cpp b/Userland/Libraries/LibWeb/HTML/HTMLOptionsCollection.cpp
index 4d0f4ea8cf2..382d07d46db 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLOptionsCollection.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLOptionsCollection.cpp
@@ -13,9 +13,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<HTMLOptionsCollection>> HTMLOptionsCollection::create(DOM::ParentNode& root, Function<bool(DOM::Element const&)> filter)
+JS::NonnullGCPtr<HTMLOptionsCollection> HTMLOptionsCollection::create(DOM::ParentNode& root, Function<bool(DOM::Element const&)> filter)
 {
-    return MUST_OR_THROW_OOM(root.heap().allocate<HTMLOptionsCollection>(root.realm(), root, move(filter)));
+    return root.heap().allocate<HTMLOptionsCollection>(root.realm(), root, move(filter));
 }
 
 HTMLOptionsCollection::HTMLOptionsCollection(DOM::ParentNode& root, Function<bool(DOM::Element const&)> filter)
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLOptionsCollection.h b/Userland/Libraries/LibWeb/HTML/HTMLOptionsCollection.h
index c631c121b4d..f990acb2b0f 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLOptionsCollection.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLOptionsCollection.h
@@ -19,7 +19,7 @@ class HTMLOptionsCollection final : public DOM::HTMLCollection {
     WEB_PLATFORM_OBJECT(HTMLOptionsCollection, DOM::HTMLCollection);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<HTMLOptionsCollection>> create(DOM::ParentNode& root, Function<bool(DOM::Element const&)> filter);
+    [[nodiscard]] static JS::NonnullGCPtr<HTMLOptionsCollection> create(DOM::ParentNode& root, Function<bool(DOM::Element const&)> filter);
     virtual ~HTMLOptionsCollection() override;
 
     WebIDL::ExceptionOr<void> add(HTMLOptionOrOptGroupElement element, Optional<HTMLElementOrElementIndex> before = {});
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.cpp
index 0600bc959d0..3dc73286242 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.cpp
@@ -86,7 +86,7 @@ void HTMLScriptElement::execute_script()
     // 3. If el's result is null, then fire an event named error at el, and return.
     if (m_result.has<ResultState::Null>()) {
         dbgln("HTMLScriptElement: Refusing to run script because the element's result is null.");
-        dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error));
         return;
     }
 
@@ -137,7 +137,7 @@ void HTMLScriptElement::execute_script()
 
     // 8. If el's from an external file is true, then fire an event named load at el.
     if (m_from_an_external_file)
-        dispatch_event(DOM::Event::create(realm(), HTML::EventNames::load).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(DOM::Event::create(realm(), HTML::EventNames::load));
 }
 
 // https://html.spec.whatwg.org/multipage/scripting.html#prepare-a-script
@@ -340,7 +340,7 @@ void HTMLScriptElement::prepare_script()
         if (m_script_type == ScriptType::ImportMap) {
             // then queue an element task on the DOM manipulation task source given el to fire an event named error at el, and return.
             queue_an_element_task(HTML::Task::Source::DOMManipulation, [this] {
-                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error));
             });
             return;
         }
@@ -352,7 +352,7 @@ void HTMLScriptElement::prepare_script()
         if (src.is_empty()) {
             dbgln("HTMLScriptElement: Refusing to run script because the src attribute is empty.");
             queue_an_element_task(HTML::Task::Source::DOMManipulation, [this] {
-                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error));
             });
             return;
         }
@@ -367,7 +367,7 @@ void HTMLScriptElement::prepare_script()
         if (!url.is_valid()) {
             dbgln("HTMLScriptElement: Refusing to run script because the src URL '{}' is invalid.", url);
             queue_an_element_task(HTML::Task::Source::DOMManipulation, [this] {
-                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error));
             });
             return;
         }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLSelectElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLSelectElement.cpp
index b5576979bf6..022c7d78d9b 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLSelectElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLSelectElement.cpp
@@ -42,7 +42,7 @@ JS::GCPtr<HTMLOptionsCollection> const& HTMLSelectElement::options()
             // the select element, and all the option element children of all the optgroup element children
             // of the select element, in tree order.
             return is<HTMLOptionElement>(element);
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return m_options;
 }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLTableElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLTableElement.cpp
index 55c8fa3aa4c..0de18caa386 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLTableElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLTableElement.cpp
@@ -272,7 +272,7 @@ JS::NonnullGCPtr<DOM::HTMLCollection> HTMLTableElement::t_bodies()
     if (!m_t_bodies) {
         m_t_bodies = DOM::HTMLCollection::create(*this, DOM::HTMLCollection::Scope::Children, [](DOM::Element const& element) {
             return element.local_name() == TagNames::tbody;
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_t_bodies;
 }
@@ -329,7 +329,7 @@ JS::NonnullGCPtr<DOM::HTMLCollection> HTMLTableElement::rows()
             }
 
             return false;
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_rows;
 }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLTableRowElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLTableRowElement.cpp
index cb4d133eb1c..62eb74a53f8 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLTableRowElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLTableRowElement.cpp
@@ -65,7 +65,7 @@ JS::NonnullGCPtr<DOM::HTMLCollection> HTMLTableRowElement::cells() const
     if (!m_cells) {
         m_cells = DOM::HTMLCollection::create(const_cast<HTMLTableRowElement&>(*this), DOM::HTMLCollection::Scope::Children, [](Element const& element) {
             return is<HTMLTableCellElement>(element);
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_cells;
 }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLTableSectionElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLTableSectionElement.cpp
index 5c02ff45301..d5ad0f23a05 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLTableSectionElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLTableSectionElement.cpp
@@ -41,7 +41,7 @@ JS::NonnullGCPtr<DOM::HTMLCollection> HTMLTableSectionElement::rows() const
     if (!m_rows) {
         m_rows = DOM::HTMLCollection::create(const_cast<HTMLTableSectionElement&>(*this), DOM::HTMLCollection::Scope::Children, [](Element const& element) {
             return is<HTMLTableRowElement>(element);
-        }).release_value_but_fixme_should_propagate_errors();
+        });
     }
     return *m_rows;
 }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLTemplateElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLTemplateElement.cpp
index 7849bf74b86..9712909d703 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLTemplateElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLTemplateElement.cpp
@@ -22,7 +22,7 @@ void HTMLTemplateElement::initialize(JS::Realm& realm)
     Base::initialize(realm);
     set_prototype(&Bindings::ensure_web_prototype<Bindings::HTMLTemplateElementPrototype>(realm, "HTMLTemplateElement"));
 
-    m_content = MUST(heap().allocate<DOM::DocumentFragment>(realm, m_document->appropriate_template_contents_owner_document()));
+    m_content = heap().allocate<DOM::DocumentFragment>(realm, m_document->appropriate_template_contents_owner_document());
     m_content->set_host(this);
 }
 
diff --git a/Userland/Libraries/LibWeb/HTML/History.cpp b/Userland/Libraries/LibWeb/HTML/History.cpp
index 48471d77282..e505cb39a86 100644
--- a/Userland/Libraries/LibWeb/HTML/History.cpp
+++ b/Userland/Libraries/LibWeb/HTML/History.cpp
@@ -10,9 +10,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<History>> History::create(JS::Realm& realm, DOM::Document& document)
+JS::NonnullGCPtr<History> History::create(JS::Realm& realm, DOM::Document& document)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<History>(realm, realm, document));
+    return realm.heap().allocate<History>(realm, realm, document);
 }
 
 History::History(JS::Realm& realm, DOM::Document& document)
diff --git a/Userland/Libraries/LibWeb/HTML/History.h b/Userland/Libraries/LibWeb/HTML/History.h
index 60dca160b0b..c11aa2b5e78 100644
--- a/Userland/Libraries/LibWeb/HTML/History.h
+++ b/Userland/Libraries/LibWeb/HTML/History.h
@@ -16,7 +16,7 @@ class History final : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(History, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<History>> create(JS::Realm&, DOM::Document&);
+    [[nodiscard]] static JS::NonnullGCPtr<History> create(JS::Realm&, DOM::Document&);
 
     virtual ~History() override;
 
diff --git a/Userland/Libraries/LibWeb/HTML/ImageData.cpp b/Userland/Libraries/LibWeb/HTML/ImageData.cpp
index 723c25e454b..04ab5b549e7 100644
--- a/Userland/Libraries/LibWeb/HTML/ImageData.cpp
+++ b/Userland/Libraries/LibWeb/HTML/ImageData.cpp
@@ -28,7 +28,7 @@ JS::GCPtr<ImageData> ImageData::create_with_size(JS::Realm& realm, int width, in
     auto bitmap_or_error = Gfx::Bitmap::create_wrapper(Gfx::BitmapFormat::RGBA8888, Gfx::IntSize(width, height), 1, width * sizeof(u32), data->data().data());
     if (bitmap_or_error.is_error())
         return nullptr;
-    return realm.heap().allocate<ImageData>(realm, realm, bitmap_or_error.release_value(), move(data)).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<ImageData>(realm, realm, bitmap_or_error.release_value(), move(data));
 }
 
 ImageData::ImageData(JS::Realm& realm, NonnullRefPtr<Gfx::Bitmap> bitmap, JS::NonnullGCPtr<JS::Uint8ClampedArray> data)
diff --git a/Userland/Libraries/LibWeb/HTML/MessageChannel.cpp b/Userland/Libraries/LibWeb/HTML/MessageChannel.cpp
index 56bdbd77dbf..97529c4dae1 100644
--- a/Userland/Libraries/LibWeb/HTML/MessageChannel.cpp
+++ b/Userland/Libraries/LibWeb/HTML/MessageChannel.cpp
@@ -13,17 +13,17 @@ namespace Web::HTML {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<MessageChannel>> MessageChannel::construct_impl(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<MessageChannel>(realm, realm));
+    return realm.heap().allocate<MessageChannel>(realm, realm);
 }
 
 MessageChannel::MessageChannel(JS::Realm& realm)
     : PlatformObject(realm)
 {
     // 1. Set this's port 1 to a new MessagePort in this's relevant Realm.
-    m_port1 = MessagePort::create(realm).release_value_but_fixme_should_propagate_errors();
+    m_port1 = MessagePort::create(realm);
 
     // 2. Set this's port 2 to a new MessagePort in this's relevant Realm.
-    m_port2 = MessagePort::create(realm).release_value_but_fixme_should_propagate_errors();
+    m_port2 = MessagePort::create(realm);
 
     // 3. Entangle this's port 1 and this's port 2.
     m_port1->entangle_with(*m_port2);
diff --git a/Userland/Libraries/LibWeb/HTML/MessageEvent.cpp b/Userland/Libraries/LibWeb/HTML/MessageEvent.cpp
index 22b7bae3fe3..777eea5afcb 100644
--- a/Userland/Libraries/LibWeb/HTML/MessageEvent.cpp
+++ b/Userland/Libraries/LibWeb/HTML/MessageEvent.cpp
@@ -9,9 +9,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<MessageEvent>> MessageEvent::create(JS::Realm& realm, FlyString const& event_name, MessageEventInit const& event_init)
+JS::NonnullGCPtr<MessageEvent> MessageEvent::create(JS::Realm& realm, FlyString const& event_name, MessageEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<MessageEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<MessageEvent>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<MessageEvent>> MessageEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, MessageEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/HTML/MessageEvent.h b/Userland/Libraries/LibWeb/HTML/MessageEvent.h
index 83c73147e42..32fbb9fc95c 100644
--- a/Userland/Libraries/LibWeb/HTML/MessageEvent.h
+++ b/Userland/Libraries/LibWeb/HTML/MessageEvent.h
@@ -22,8 +22,8 @@ class MessageEvent : public DOM::Event {
     WEB_PLATFORM_OBJECT(MessageEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<MessageEvent>> create(JS::Realm&, FlyString const& event_name, MessageEventInit const& event_init = {});
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<MessageEvent>> construct_impl(JS::Realm&, FlyString const& event_name, MessageEventInit const& event_init);
+    [[nodiscard]] static JS::NonnullGCPtr<MessageEvent> create(JS::Realm&, FlyString const& event_name, MessageEventInit const& = {});
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<MessageEvent>> construct_impl(JS::Realm&, FlyString const& event_name, MessageEventInit const&);
 
     MessageEvent(JS::Realm&, FlyString const& event_name, MessageEventInit const& event_init);
     virtual ~MessageEvent() override;
diff --git a/Userland/Libraries/LibWeb/HTML/MessagePort.cpp b/Userland/Libraries/LibWeb/HTML/MessagePort.cpp
index 37f2598ac2a..5d65193e7b6 100644
--- a/Userland/Libraries/LibWeb/HTML/MessagePort.cpp
+++ b/Userland/Libraries/LibWeb/HTML/MessagePort.cpp
@@ -14,9 +14,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<MessagePort>> MessagePort::create(JS::Realm& realm)
+JS::NonnullGCPtr<MessagePort> MessagePort::create(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<MessagePort>(realm, realm));
+    return realm.heap().allocate<MessagePort>(realm, realm);
 }
 
 MessagePort::MessagePort(JS::Realm& realm)
@@ -97,7 +97,7 @@ void MessagePort::post_message(JS::Value message)
         MessageEventInit event_init {};
         event_init.data = message;
         event_init.origin = "<origin>"_string;
-        target_port->dispatch_event(MessageEvent::create(target_port->realm(), HTML::EventNames::message, event_init).release_value_but_fixme_should_propagate_errors());
+        target_port->dispatch_event(MessageEvent::create(target_port->realm(), HTML::EventNames::message, event_init));
     }));
 }
 
diff --git a/Userland/Libraries/LibWeb/HTML/MessagePort.h b/Userland/Libraries/LibWeb/HTML/MessagePort.h
index 82131a72972..7d5784d3407 100644
--- a/Userland/Libraries/LibWeb/HTML/MessagePort.h
+++ b/Userland/Libraries/LibWeb/HTML/MessagePort.h
@@ -27,7 +27,7 @@ class MessagePort final : public DOM::EventTarget {
     WEB_PLATFORM_OBJECT(MessagePort, DOM::EventTarget);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<MessagePort>> create(JS::Realm&);
+    [[nodiscard]] static JS::NonnullGCPtr<MessagePort> create(JS::Realm&);
 
     virtual ~MessagePort() override;
 
diff --git a/Userland/Libraries/LibWeb/HTML/Navigator.cpp b/Userland/Libraries/LibWeb/HTML/Navigator.cpp
index ff2efaa1459..f24b3dfb32d 100644
--- a/Userland/Libraries/LibWeb/HTML/Navigator.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Navigator.cpp
@@ -15,9 +15,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Navigator>> Navigator::create(JS::Realm& realm)
+JS::NonnullGCPtr<Navigator> Navigator::create(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Navigator>(realm, realm));
+    return realm.heap().allocate<Navigator>(realm, realm);
 }
 
 Navigator::Navigator(JS::Realm& realm)
@@ -59,17 +59,17 @@ void Navigator::visit_edges(Cell::Visitor& visitor)
     visitor.visit(m_plugin_array);
 }
 
-JS::ThrowCompletionOr<JS::NonnullGCPtr<MimeTypeArray>> Navigator::mime_types()
+JS::NonnullGCPtr<MimeTypeArray> Navigator::mime_types()
 {
     if (!m_mime_type_array)
-        m_mime_type_array = TRY(heap().allocate<MimeTypeArray>(realm(), realm()));
+        m_mime_type_array = heap().allocate<MimeTypeArray>(realm(), realm());
     return *m_mime_type_array;
 }
 
-JS::ThrowCompletionOr<JS::NonnullGCPtr<PluginArray>> Navigator::plugins()
+JS::NonnullGCPtr<PluginArray> Navigator::plugins()
 {
     if (!m_plugin_array)
-        m_plugin_array = TRY(heap().allocate<PluginArray>(realm(), realm()));
+        m_plugin_array = heap().allocate<PluginArray>(realm(), realm());
     return *m_plugin_array;
 }
 
diff --git a/Userland/Libraries/LibWeb/HTML/Navigator.h b/Userland/Libraries/LibWeb/HTML/Navigator.h
index 4741e895051..640fb6b965b 100644
--- a/Userland/Libraries/LibWeb/HTML/Navigator.h
+++ b/Userland/Libraries/LibWeb/HTML/Navigator.h
@@ -24,7 +24,7 @@ class Navigator : public Bindings::PlatformObject
     WEB_PLATFORM_OBJECT(Navigator, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Navigator>> create(JS::Realm&);
+    [[nodiscard]] static JS::NonnullGCPtr<Navigator> create(JS::Realm&);
 
     // FIXME: Implement NavigatorContentUtilsMixin
 
@@ -41,8 +41,8 @@ public:
 
     bool webdriver() const;
 
-    JS::ThrowCompletionOr<JS::NonnullGCPtr<MimeTypeArray>> mime_types();
-    JS::ThrowCompletionOr<JS::NonnullGCPtr<PluginArray>> plugins();
+    [[nodiscard]] JS::NonnullGCPtr<MimeTypeArray> mime_types();
+    [[nodiscard]] JS::NonnullGCPtr<PluginArray> plugins();
 
     virtual ~Navigator() override;
 
diff --git a/Userland/Libraries/LibWeb/HTML/PageTransitionEvent.cpp b/Userland/Libraries/LibWeb/HTML/PageTransitionEvent.cpp
index b9e3353c649..c035476171c 100644
--- a/Userland/Libraries/LibWeb/HTML/PageTransitionEvent.cpp
+++ b/Userland/Libraries/LibWeb/HTML/PageTransitionEvent.cpp
@@ -9,9 +9,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<PageTransitionEvent>> PageTransitionEvent::create(JS::Realm& realm, FlyString const& event_name, PageTransitionEventInit const& event_init)
+JS::NonnullGCPtr<PageTransitionEvent> PageTransitionEvent::create(JS::Realm& realm, FlyString const& event_name, PageTransitionEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<PageTransitionEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<PageTransitionEvent>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<PageTransitionEvent>> PageTransitionEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, PageTransitionEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/HTML/PageTransitionEvent.h b/Userland/Libraries/LibWeb/HTML/PageTransitionEvent.h
index 1227edc2cac..a8f5634c734 100644
--- a/Userland/Libraries/LibWeb/HTML/PageTransitionEvent.h
+++ b/Userland/Libraries/LibWeb/HTML/PageTransitionEvent.h
@@ -19,8 +19,8 @@ class PageTransitionEvent final : public DOM::Event {
     WEB_PLATFORM_OBJECT(PageTransitionEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<PageTransitionEvent>> create(JS::Realm&, FlyString const& event_name, PageTransitionEventInit const& event_init);
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<PageTransitionEvent>> construct_impl(JS::Realm&, FlyString const& event_name, PageTransitionEventInit const& event_init);
+    [[nodiscard]] static JS::NonnullGCPtr<PageTransitionEvent> create(JS::Realm&, FlyString const& event_name, PageTransitionEventInit const&);
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<PageTransitionEvent>> construct_impl(JS::Realm&, FlyString const& event_name, PageTransitionEventInit const&);
 
     PageTransitionEvent(JS::Realm&, FlyString const& event_name, PageTransitionEventInit const& event_init);
 
diff --git a/Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.cpp b/Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.cpp
index 1fedcc8dd77..74a688b68c7 100644
--- a/Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.cpp
@@ -109,7 +109,7 @@ JS::GCPtr<DOM::Attr> prescan_get_attribute(DOM::Document& document, ByteBuffer c
         } else if (input[position] == '\t' || input[position] == '\n' || input[position] == '\f' || input[position] == '\r' || input[position] == ' ')
             goto spaces;
         else if (input[position] == '/' || input[position] == '>')
-            return *DOM::Attr::create(document, attribute_name.to_deprecated_string(), "").release_value_but_fixme_should_propagate_errors();
+            return *DOM::Attr::create(document, attribute_name.to_deprecated_string(), "");
         else
             attribute_name.append_as_lowercase(input[position]);
         ++position;
@@ -121,7 +121,7 @@ spaces:
     if (!prescan_skip_whitespace_and_slashes(input, position))
         return {};
     if (input[position] != '=')
-        return DOM::Attr::create(document, attribute_name.to_deprecated_string(), "").release_value_but_fixme_should_propagate_errors();
+        return DOM::Attr::create(document, attribute_name.to_deprecated_string(), "");
     ++position;
 
 value:
@@ -134,13 +134,13 @@ value:
         ++position;
         for (; !prescan_should_abort(input, position); ++position) {
             if (input[position] == quote_character)
-                return DOM::Attr::create(document, attribute_name.to_deprecated_string(), attribute_value.to_deprecated_string()).release_value_but_fixme_should_propagate_errors();
+                return DOM::Attr::create(document, attribute_name.to_deprecated_string(), attribute_value.to_deprecated_string());
             else
                 attribute_value.append_as_lowercase(input[position]);
         }
         return {};
     } else if (input[position] == '>')
-        return DOM::Attr::create(document, attribute_name.to_deprecated_string(), "").release_value_but_fixme_should_propagate_errors();
+        return DOM::Attr::create(document, attribute_name.to_deprecated_string(), "");
     else
         attribute_value.append_as_lowercase(input[position]);
 
@@ -150,7 +150,7 @@ value:
 
     for (; !prescan_should_abort(input, position); ++position) {
         if (input[position] == '\t' || input[position] == '\n' || input[position] == '\f' || input[position] == '\r' || input[position] == ' ' || input[position] == '>')
-            return DOM::Attr::create(document, attribute_name.to_deprecated_string(), attribute_value.to_deprecated_string()).release_value_but_fixme_should_propagate_errors();
+            return DOM::Attr::create(document, attribute_name.to_deprecated_string(), attribute_value.to_deprecated_string());
         else
             attribute_value.append_as_lowercase(input[position]);
     }
diff --git a/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp b/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp
index 6578a7c9e43..96747702a31 100644
--- a/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp
@@ -281,7 +281,7 @@ void HTMLParser::the_end()
         document->load_timing_info().dom_content_loaded_event_start_time = HighResolutionTime::unsafe_shared_current_time();
 
         // 2. Fire an event named DOMContentLoaded at the Document object, with its bubbles attribute initialized to true.
-        auto content_loaded_event = DOM::Event::create(document->realm(), HTML::EventNames::DOMContentLoaded).release_value_but_fixme_should_propagate_errors();
+        auto content_loaded_event = DOM::Event::create(document->realm(), HTML::EventNames::DOMContentLoaded);
         content_loaded_event->set_bubbles(true);
         document->dispatch_event(content_loaded_event);
 
@@ -322,7 +322,7 @@ void HTMLParser::the_end()
         // 5. Fire an event named load at window, with legacy target override flag set.
         // FIXME: The legacy target override flag is currently set by a virtual override of dispatch_event()
         //        We should reorganize this so that the flag appears explicitly here instead.
-        window->dispatch_event(DOM::Event::create(document->realm(), HTML::EventNames::load).release_value_but_fixme_should_propagate_errors());
+        window->dispatch_event(DOM::Event::create(document->realm(), HTML::EventNames::load));
 
         // FIXME: 6. Invoke WebDriver BiDi load complete with the Document's browsing context, and a new WebDriver BiDi navigation status whose id is the Document object's navigation id, status is "complete", and url is the Document object's URL.
 
@@ -490,13 +490,13 @@ void HTMLParser::handle_initial(HTMLToken& token)
     }
 
     if (token.is_comment()) {
-        auto comment = realm().heap().allocate<DOM::Comment>(realm(), document(), token.comment()).release_allocated_value_but_fixme_should_propagate_errors();
+        auto comment = realm().heap().allocate<DOM::Comment>(realm(), document(), token.comment());
         MUST(document().append_child(*comment));
         return;
     }
 
     if (token.is_doctype()) {
-        auto doctype = realm().heap().allocate<DOM::DocumentType>(realm(), document()).release_allocated_value_but_fixme_should_propagate_errors();
+        auto doctype = realm().heap().allocate<DOM::DocumentType>(realm(), document());
         doctype->set_name(token.doctype_data().name);
         doctype->set_public_id(token.doctype_data().public_identifier);
         doctype->set_system_id(token.doctype_data().system_identifier);
@@ -525,7 +525,7 @@ void HTMLParser::handle_before_html(HTMLToken& token)
     // -> A comment token
     if (token.is_comment()) {
         // Insert a comment as the last child of the Document object.
-        auto comment = realm().heap().allocate<DOM::Comment>(realm(), document(), token.comment()).release_allocated_value_but_fixme_should_propagate_errors();
+        auto comment = realm().heap().allocate<DOM::Comment>(realm(), document(), token.comment());
         MUST(document().append_child(*comment));
         return;
     }
@@ -822,7 +822,7 @@ AnythingElse:
 void HTMLParser::insert_comment(HTMLToken& token)
 {
     auto adjusted_insertion_location = find_appropriate_place_for_inserting_node();
-    adjusted_insertion_location.parent->insert_before(realm().heap().allocate<DOM::Comment>(realm(), document(), token.comment()).release_allocated_value_but_fixme_should_propagate_errors(), adjusted_insertion_location.insert_before_sibling);
+    adjusted_insertion_location.parent->insert_before(realm().heap().allocate<DOM::Comment>(realm(), document(), token.comment()), adjusted_insertion_location.insert_before_sibling);
 }
 
 void HTMLParser::handle_in_head(HTMLToken& token)
@@ -1004,7 +1004,7 @@ DOM::Text* HTMLParser::find_character_insertion_node()
     if (adjusted_insertion_location.insert_before_sibling) {
         if (adjusted_insertion_location.insert_before_sibling->previous_sibling() && adjusted_insertion_location.insert_before_sibling->previous_sibling()->is_text())
             return static_cast<DOM::Text*>(adjusted_insertion_location.insert_before_sibling->previous_sibling());
-        auto new_text_node = realm().heap().allocate<DOM::Text>(realm(), document(), "").release_allocated_value_but_fixme_should_propagate_errors();
+        auto new_text_node = realm().heap().allocate<DOM::Text>(realm(), document(), "");
         adjusted_insertion_location.parent->insert_before(*new_text_node, *adjusted_insertion_location.insert_before_sibling);
         return new_text_node;
     }
@@ -1012,7 +1012,7 @@ DOM::Text* HTMLParser::find_character_insertion_node()
         return nullptr;
     if (adjusted_insertion_location.parent->last_child() && adjusted_insertion_location.parent->last_child()->is_text())
         return verify_cast<DOM::Text>(adjusted_insertion_location.parent->last_child());
-    auto new_text_node = realm().heap().allocate<DOM::Text>(realm(), document(), "").release_allocated_value_but_fixme_should_propagate_errors();
+    auto new_text_node = realm().heap().allocate<DOM::Text>(realm(), document(), "");
     MUST(adjusted_insertion_location.parent->append_child(*new_text_node));
     return new_text_node;
 }
@@ -1137,7 +1137,7 @@ void HTMLParser::handle_after_body(HTMLToken& token)
 
     if (token.is_comment()) {
         auto& insertion_location = m_stack_of_open_elements.first();
-        MUST(insertion_location.append_child(realm().heap().allocate<DOM::Comment>(realm(), document(), token.comment()).release_allocated_value_but_fixme_should_propagate_errors()));
+        MUST(insertion_location.append_child(realm().heap().allocate<DOM::Comment>(realm(), document(), token.comment())));
         return;
     }
 
@@ -1173,7 +1173,7 @@ void HTMLParser::handle_after_body(HTMLToken& token)
 void HTMLParser::handle_after_after_body(HTMLToken& token)
 {
     if (token.is_comment()) {
-        auto comment = realm().heap().allocate<DOM::Comment>(realm(), document(), token.comment()).release_allocated_value_but_fixme_should_propagate_errors();
+        auto comment = realm().heap().allocate<DOM::Comment>(realm(), document(), token.comment());
         MUST(document().append_child(*comment));
         return;
     }
@@ -3402,7 +3402,7 @@ void HTMLParser::handle_after_frameset(HTMLToken& token)
 void HTMLParser::handle_after_after_frameset(HTMLToken& token)
 {
     if (token.is_comment()) {
-        auto comment = document().heap().allocate<DOM::Comment>(document().realm(), document(), token.comment()).release_allocated_value_but_fixme_should_propagate_errors();
+        auto comment = document().heap().allocate<DOM::Comment>(document().realm(), document(), token.comment());
         MUST(document().append_child(comment));
         return;
     }
@@ -3669,7 +3669,7 @@ DOM::Document& HTMLParser::document()
 Vector<JS::Handle<DOM::Node>> HTMLParser::parse_html_fragment(DOM::Element& context_element, StringView markup)
 {
     // 1. Create a new Document node, and mark it as being an HTML document.
-    auto temp_document = DOM::Document::create(context_element.realm()).release_value_but_fixme_should_propagate_errors();
+    auto temp_document = DOM::Document::create(context_element.realm());
     temp_document->set_document_type(DOM::Document::Type::HTML);
 
     temp_document->set_is_temporary_document_for_fragment_parsing({});
diff --git a/Userland/Libraries/LibWeb/HTML/Path2D.cpp b/Userland/Libraries/LibWeb/HTML/Path2D.cpp
index 636d2d1ebdc..9a565af378e 100644
--- a/Userland/Libraries/LibWeb/HTML/Path2D.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Path2D.cpp
@@ -16,7 +16,7 @@ namespace Web::HTML {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<Path2D>> Path2D::construct_impl(JS::Realm& realm, Optional<Variant<JS::Handle<Path2D>, DeprecatedString>> const& path)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Path2D>(realm, realm, path));
+    return realm.heap().allocate<Path2D>(realm, realm, path);
 }
 
 // https://html.spec.whatwg.org/multipage/canvas.html#dom-path2d
diff --git a/Userland/Libraries/LibWeb/HTML/PromiseRejectionEvent.cpp b/Userland/Libraries/LibWeb/HTML/PromiseRejectionEvent.cpp
index 23322f324f4..bbe4f7bcd15 100644
--- a/Userland/Libraries/LibWeb/HTML/PromiseRejectionEvent.cpp
+++ b/Userland/Libraries/LibWeb/HTML/PromiseRejectionEvent.cpp
@@ -9,9 +9,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<PromiseRejectionEvent>> PromiseRejectionEvent::create(JS::Realm& realm, FlyString const& event_name, PromiseRejectionEventInit const& event_init)
+JS::NonnullGCPtr<PromiseRejectionEvent> PromiseRejectionEvent::create(JS::Realm& realm, FlyString const& event_name, PromiseRejectionEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<PromiseRejectionEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<PromiseRejectionEvent>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<PromiseRejectionEvent>> PromiseRejectionEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, PromiseRejectionEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/HTML/PromiseRejectionEvent.h b/Userland/Libraries/LibWeb/HTML/PromiseRejectionEvent.h
index 5e0ac122a36..2edcae286d6 100644
--- a/Userland/Libraries/LibWeb/HTML/PromiseRejectionEvent.h
+++ b/Userland/Libraries/LibWeb/HTML/PromiseRejectionEvent.h
@@ -24,8 +24,8 @@ class PromiseRejectionEvent final : public DOM::Event {
     WEB_PLATFORM_OBJECT(PromiseRejectionEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<PromiseRejectionEvent>> create(JS::Realm&, FlyString const& event_name, PromiseRejectionEventInit const& event_init = {});
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<PromiseRejectionEvent>> construct_impl(JS::Realm&, FlyString const& event_name, PromiseRejectionEventInit const& event_init);
+    [[nodiscard]] static JS::NonnullGCPtr<PromiseRejectionEvent> create(JS::Realm&, FlyString const& event_name, PromiseRejectionEventInit const& = {});
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<PromiseRejectionEvent>> construct_impl(JS::Realm&, FlyString const& event_name, PromiseRejectionEventInit const&);
 
     virtual ~PromiseRejectionEvent() override;
 
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/Environments.cpp b/Userland/Libraries/LibWeb/HTML/Scripting/Environments.cpp
index 9366741fd2a..2bf65050541 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/Environments.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/Environments.cpp
@@ -259,7 +259,7 @@ void EnvironmentSettingsObject::notify_about_rejected_promises(Badge<EventLoop>)
             // FIXME: This currently assumes that global is a WindowObject.
             auto& window = verify_cast<HTML::Window>(global);
 
-            auto promise_rejection_event = PromiseRejectionEvent::create(window.realm(), HTML::EventNames::unhandledrejection, event_init).release_value_but_fixme_should_propagate_errors();
+            auto promise_rejection_event = PromiseRejectionEvent::create(window.realm(), HTML::EventNames::unhandledrejection, event_init);
 
             bool not_handled = window.dispatch_event(*promise_rejection_event);
 
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/ModuleScript.cpp b/Userland/Libraries/LibWeb/HTML/Scripting/ModuleScript.cpp
index f5ea81c6014..0d63536f20a 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/ModuleScript.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/ModuleScript.cpp
@@ -37,7 +37,7 @@ WebIDL::ExceptionOr<JS::GCPtr<JavaScriptModuleScript>> JavaScriptModuleScript::c
     auto& realm = settings_object.realm();
 
     // 2. Let script be a new module script that this algorithm will subsequently initialize.
-    auto script = MUST_OR_THROW_OOM(realm.heap().allocate<JavaScriptModuleScript>(realm, move(base_url), filename, settings_object));
+    auto script = realm.heap().allocate<JavaScriptModuleScript>(realm, move(base_url), filename, settings_object);
 
     // 3. Set script's settings object to settings.
     // NOTE: This was already done when constructing.
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.cpp b/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.cpp
index 105f766d201..0fe78ec19e0 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.cpp
@@ -27,7 +27,7 @@ void WindowEnvironmentSettingsObject::visit_edges(JS::Cell::Visitor& visitor)
 }
 
 // https://html.spec.whatwg.org/multipage/window-object.html#set-up-a-window-environment-settings-object
-WebIDL::ExceptionOr<void> WindowEnvironmentSettingsObject::setup(AK::URL const& creation_url, NonnullOwnPtr<JS::ExecutionContext> execution_context, Optional<Environment> reserved_environment, AK::URL top_level_creation_url, Origin top_level_origin)
+void WindowEnvironmentSettingsObject::setup(AK::URL const& creation_url, NonnullOwnPtr<JS::ExecutionContext> execution_context, Optional<Environment> reserved_environment, AK::URL top_level_creation_url, Origin top_level_origin)
 {
     // 1. Let realm be the value of execution context's Realm component.
     auto realm = execution_context->realm;
@@ -38,7 +38,7 @@ WebIDL::ExceptionOr<void> WindowEnvironmentSettingsObject::setup(AK::URL const&
 
     // 3. Let settings object be a new environment settings object whose algorithms are defined as follows:
     // NOTE: See the functions defined for this class.
-    auto settings_object = MUST_OR_THROW_OOM(realm->heap().allocate<WindowEnvironmentSettingsObject>(*realm, window, move(execution_context)));
+    auto settings_object = realm->heap().allocate<WindowEnvironmentSettingsObject>(*realm, window, move(execution_context));
 
     // 4. If reservedEnvironment is non-null, then:
     if (reserved_environment.has_value()) {
@@ -71,15 +71,13 @@ WebIDL::ExceptionOr<void> WindowEnvironmentSettingsObject::setup(AK::URL const&
 
     // 7. Set realm's [[HostDefined]] field to settings object.
     // Non-Standard: We store the ESO next to the web intrinsics in a custom HostDefined object
-    auto intrinsics = MUST_OR_THROW_OOM(realm->heap().allocate<Bindings::Intrinsics>(*realm, *realm));
+    auto intrinsics = realm->heap().allocate<Bindings::Intrinsics>(*realm, *realm);
     auto host_defined = make<Bindings::HostDefined>(settings_object, intrinsics);
     realm->set_host_defined(move(host_defined));
 
     // Non-Standard: We cannot fully initialize window object until *after* the we set up
     //    the realm's [[HostDefined]] internal slot as the internal slot contains the web platform intrinsics
-    TRY(window.initialize_web_interfaces({}));
-
-    return {};
+    MUST(window.initialize_web_interfaces({}));
 }
 
 // https://html.spec.whatwg.org/multipage/window-object.html#script-settings-for-window-objects:responsible-document
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.h b/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.h
index 89399ee5ec6..da0ae20905a 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.h
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.h
@@ -15,7 +15,7 @@ class WindowEnvironmentSettingsObject final : public EnvironmentSettingsObject {
     JS_CELL(WindowEnvironmentSettingsObject, EnvironmentSettingsObject);
 
 public:
-    static WebIDL::ExceptionOr<void> setup(AK::URL const& creation_url, NonnullOwnPtr<JS::ExecutionContext>, Optional<Environment>, AK::URL top_level_creation_url, Origin top_level_origin);
+    static void setup(AK::URL const& creation_url, NonnullOwnPtr<JS::ExecutionContext>, Optional<Environment>, AK::URL top_level_creation_url, Origin top_level_origin);
 
     virtual ~WindowEnvironmentSettingsObject() override;
 
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/WorkerEnvironmentSettingsObject.h b/Userland/Libraries/LibWeb/HTML/Scripting/WorkerEnvironmentSettingsObject.h
index 4412444e758..40b3191af82 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/WorkerEnvironmentSettingsObject.h
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/WorkerEnvironmentSettingsObject.h
@@ -27,10 +27,10 @@ public:
     {
         auto realm = execution_context->realm;
         VERIFY(realm);
-        auto settings_object = realm->heap().allocate<WorkerEnvironmentSettingsObject>(*realm, move(execution_context)).release_allocated_value_but_fixme_should_propagate_errors();
+        auto settings_object = realm->heap().allocate<WorkerEnvironmentSettingsObject>(*realm, move(execution_context));
         settings_object->target_browsing_context = nullptr;
 
-        auto intrinsics = realm->heap().allocate<Bindings::Intrinsics>(*realm, *realm).release_allocated_value_but_fixme_should_propagate_errors();
+        auto intrinsics = realm->heap().allocate<Bindings::Intrinsics>(*realm, *realm);
         auto host_defined = make<Bindings::HostDefined>(settings_object, intrinsics);
         realm->set_host_defined(move(host_defined));
 
diff --git a/Userland/Libraries/LibWeb/HTML/Storage.cpp b/Userland/Libraries/LibWeb/HTML/Storage.cpp
index b26b143e14f..f10bb8e690c 100644
--- a/Userland/Libraries/LibWeb/HTML/Storage.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Storage.cpp
@@ -11,9 +11,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Storage>> Storage::create(JS::Realm& realm)
+JS::NonnullGCPtr<Storage> Storage::create(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Storage>(realm, realm));
+    return realm.heap().allocate<Storage>(realm, realm);
 }
 
 Storage::Storage(JS::Realm& realm)
diff --git a/Userland/Libraries/LibWeb/HTML/Storage.h b/Userland/Libraries/LibWeb/HTML/Storage.h
index d02f942f1a9..86128a96aad 100644
--- a/Userland/Libraries/LibWeb/HTML/Storage.h
+++ b/Userland/Libraries/LibWeb/HTML/Storage.h
@@ -17,7 +17,7 @@ class Storage : public Bindings::LegacyPlatformObject {
     WEB_PLATFORM_OBJECT(Storage, Bindings::LegacyPlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Storage>> create(JS::Realm&);
+    [[nodiscard]] static JS::NonnullGCPtr<Storage> create(JS::Realm&);
     ~Storage();
 
     size_t length() const;
diff --git a/Userland/Libraries/LibWeb/HTML/StructuredSerialize.cpp b/Userland/Libraries/LibWeb/HTML/StructuredSerialize.cpp
index cfb89bf7ae5..556c009b5ce 100644
--- a/Userland/Libraries/LibWeb/HTML/StructuredSerialize.cpp
+++ b/Userland/Libraries/LibWeb/HTML/StructuredSerialize.cpp
@@ -235,7 +235,7 @@ public:
             case ValueTag::StringObject: {
                 auto* realm = m_vm.current_realm();
                 auto string = TRY(deserialize_string_primitive(m_vm, m_vector, position));
-                m_memory.append(TRY(JS::StringObject::create(*realm, string, realm->intrinsics().string_prototype())));
+                m_memory.append(JS::StringObject::create(*realm, string, realm->intrinsics().string_prototype()));
                 break;
             }
             case ValueTag::DateObject: {
diff --git a/Userland/Libraries/LibWeb/HTML/SubmitEvent.cpp b/Userland/Libraries/LibWeb/HTML/SubmitEvent.cpp
index 0417f383a3f..838b06624d2 100644
--- a/Userland/Libraries/LibWeb/HTML/SubmitEvent.cpp
+++ b/Userland/Libraries/LibWeb/HTML/SubmitEvent.cpp
@@ -9,9 +9,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<SubmitEvent>> SubmitEvent::create(JS::Realm& realm, FlyString const& event_name, SubmitEventInit const& event_init)
+JS::NonnullGCPtr<SubmitEvent> SubmitEvent::create(JS::Realm& realm, FlyString const& event_name, SubmitEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<SubmitEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<SubmitEvent>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<SubmitEvent>> SubmitEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, SubmitEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/HTML/SubmitEvent.h b/Userland/Libraries/LibWeb/HTML/SubmitEvent.h
index f48dccd169d..a37775a5603 100644
--- a/Userland/Libraries/LibWeb/HTML/SubmitEvent.h
+++ b/Userland/Libraries/LibWeb/HTML/SubmitEvent.h
@@ -19,7 +19,7 @@ class SubmitEvent final : public DOM::Event {
     WEB_PLATFORM_OBJECT(SubmitEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<SubmitEvent>> create(JS::Realm&, FlyString const& event_name, SubmitEventInit const& event_init);
+    [[nodiscard]] static JS::NonnullGCPtr<SubmitEvent> create(JS::Realm&, FlyString const& event_name, SubmitEventInit const& event_init);
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<SubmitEvent>> construct_impl(JS::Realm&, FlyString const& event_name, SubmitEventInit const& event_init);
 
     virtual ~SubmitEvent() override;
diff --git a/Userland/Libraries/LibWeb/HTML/TextMetrics.cpp b/Userland/Libraries/LibWeb/HTML/TextMetrics.cpp
index c37feeaa34c..e520a0c01e5 100644
--- a/Userland/Libraries/LibWeb/HTML/TextMetrics.cpp
+++ b/Userland/Libraries/LibWeb/HTML/TextMetrics.cpp
@@ -10,9 +10,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<TextMetrics>> TextMetrics::create(JS::Realm& realm)
+JS::NonnullGCPtr<TextMetrics> TextMetrics::create(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<TextMetrics>(realm, realm));
+    return realm.heap().allocate<TextMetrics>(realm, realm);
 }
 
 TextMetrics::TextMetrics(JS::Realm& realm)
diff --git a/Userland/Libraries/LibWeb/HTML/TextMetrics.h b/Userland/Libraries/LibWeb/HTML/TextMetrics.h
index 693ea4ad13e..fe4b96d05ee 100644
--- a/Userland/Libraries/LibWeb/HTML/TextMetrics.h
+++ b/Userland/Libraries/LibWeb/HTML/TextMetrics.h
@@ -14,7 +14,7 @@ class TextMetrics : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(TextMetrics, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<TextMetrics>> create(JS::Realm&);
+    [[nodiscard]] static JS::NonnullGCPtr<TextMetrics> create(JS::Realm&);
 
     virtual ~TextMetrics() override;
 
diff --git a/Userland/Libraries/LibWeb/HTML/TrackEvent.cpp b/Userland/Libraries/LibWeb/HTML/TrackEvent.cpp
index 7a0f700c950..40e469738f8 100644
--- a/Userland/Libraries/LibWeb/HTML/TrackEvent.cpp
+++ b/Userland/Libraries/LibWeb/HTML/TrackEvent.cpp
@@ -10,9 +10,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> TrackEvent::create(JS::Realm& realm, FlyString const& event_name, TrackEventInit event_init)
+JS::NonnullGCPtr<TrackEvent> TrackEvent::create(JS::Realm& realm, FlyString const& event_name, TrackEventInit event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<TrackEvent>(realm, realm, event_name, move(event_init)));
+    return realm.heap().allocate<TrackEvent>(realm, realm, event_name, move(event_init));
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> TrackEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, TrackEventInit event_init)
diff --git a/Userland/Libraries/LibWeb/HTML/TrackEvent.h b/Userland/Libraries/LibWeb/HTML/TrackEvent.h
index 3af9efab42c..5e03d7456c5 100644
--- a/Userland/Libraries/LibWeb/HTML/TrackEvent.h
+++ b/Userland/Libraries/LibWeb/HTML/TrackEvent.h
@@ -23,8 +23,8 @@ class TrackEvent : public DOM::Event {
     WEB_PLATFORM_OBJECT(TrackEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> create(JS::Realm&, FlyString const& event_name, TrackEventInit event_init = {});
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> construct_impl(JS::Realm&, FlyString const& event_name, TrackEventInit event_init);
+    [[nodiscard]] static JS::NonnullGCPtr<TrackEvent> create(JS::Realm&, FlyString const& event_name, TrackEventInit = {});
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> construct_impl(JS::Realm&, FlyString const& event_name, TrackEventInit);
 
     // https://html.spec.whatwg.org/multipage/media.html#dom-trackevent-track
     Variant<Empty, JS::Handle<VideoTrack>, JS::Handle<AudioTrack>> track() const;
diff --git a/Userland/Libraries/LibWeb/HTML/VideoTrack.cpp b/Userland/Libraries/LibWeb/HTML/VideoTrack.cpp
index ac7758f54b6..4e5f3bf05fb 100644
--- a/Userland/Libraries/LibWeb/HTML/VideoTrack.cpp
+++ b/Userland/Libraries/LibWeb/HTML/VideoTrack.cpp
@@ -153,7 +153,7 @@ void VideoTrack::set_selected(bool selected)
 
         if (previously_unselected_track_is_selected || selected_track_was_unselected_without_another_selection) {
             m_media_element->queue_a_media_element_task([this]() {
-                m_video_track_list->dispatch_event(DOM::Event::create(realm(), HTML::EventNames::change).release_value_but_fixme_should_propagate_errors());
+                m_video_track_list->dispatch_event(DOM::Event::create(realm(), HTML::EventNames::change));
             });
         }
     }
diff --git a/Userland/Libraries/LibWeb/HTML/Window.cpp b/Userland/Libraries/LibWeb/HTML/Window.cpp
index 6889b18bc66..6b1fbc9e94e 100644
--- a/Userland/Libraries/LibWeb/HTML/Window.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Window.cpp
@@ -84,9 +84,9 @@ private:
     u32 m_handle { 0 };
 };
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Window>> Window::create(JS::Realm& realm)
+JS::NonnullGCPtr<Window> Window::create(JS::Realm& realm)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<Window>(realm, realm));
+    return realm.heap().allocate<Window>(realm, realm);
 }
 
 Window::Window(JS::Realm& realm)
@@ -577,7 +577,7 @@ void Window::fire_a_page_transition_event(FlyString const& event_name, bool pers
     // with the persisted attribute initialized to persisted,
     PageTransitionEventInit event_init {};
     event_init.persisted = persisted;
-    auto event = PageTransitionEvent::create(associated_document().realm(), event_name, event_init).release_value_but_fixme_should_propagate_errors();
+    auto event = PageTransitionEvent::create(associated_document().realm(), event_name, event_init);
 
     // ...the cancelable attribute initialized to true,
     event->set_cancelable(true);
@@ -593,15 +593,10 @@ void Window::fire_a_page_transition_event(FlyString const& event_name, bool pers
 WebIDL::ExceptionOr<JS::NonnullGCPtr<Storage>> Window::local_storage()
 {
     // FIXME: Implement according to spec.
-    auto& vm = this->vm();
-
     static HashMap<Origin, JS::Handle<Storage>> local_storage_per_origin;
-    auto storage = TRY_OR_THROW_OOM(vm, local_storage_per_origin.try_ensure(associated_document().origin(), [this]() -> ErrorOr<JS::Handle<Storage>> {
-        auto storage_or_exception = Storage::create(realm());
-        if (storage_or_exception.is_exception())
-            return Error::from_errno(ENOMEM);
-        return *storage_or_exception.release_value();
-    }));
+    auto storage = local_storage_per_origin.ensure(associated_document().origin(), [this]() -> JS::Handle<Storage> {
+        return Storage::create(realm());
+    });
     return JS::NonnullGCPtr { *storage };
 }
 
@@ -609,15 +604,10 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Storage>> Window::local_storage()
 WebIDL::ExceptionOr<JS::NonnullGCPtr<Storage>> Window::session_storage()
 {
     // FIXME: Implement according to spec.
-    auto& vm = this->vm();
-
     static HashMap<Origin, JS::Handle<Storage>> session_storage_per_origin;
-    auto storage = TRY_OR_THROW_OOM(vm, session_storage_per_origin.try_ensure(associated_document().origin(), [this]() -> ErrorOr<JS::Handle<Storage>> {
-        auto storage_or_exception = Storage::create(realm());
-        if (storage_or_exception.is_exception())
-            return Error::from_errno(ENOMEM);
-        return *storage_or_exception.release_value();
-    }));
+    auto storage = session_storage_per_origin.ensure(associated_document().origin(), [this]() -> JS::Handle<Storage> {
+        return Storage::create(realm());
+    });
     return JS::NonnullGCPtr { *storage };
 }
 
@@ -680,7 +670,7 @@ void Window::invoke_idle_callbacks()
         // 1. Pop the top callback from window's list of runnable idle callbacks.
         auto callback = m_runnable_idle_callbacks.take_first();
         // 2. Let deadlineArg be a new IdleDeadline whose [get deadline time algorithm] is getDeadline.
-        auto deadline_arg = RequestIdleCallback::IdleDeadline::create(realm()).release_value_but_fixme_should_propagate_errors();
+        auto deadline_arg = RequestIdleCallback::IdleDeadline::create(realm());
         // 3. Call callback with deadlineArg as its argument. If an uncaught runtime script error occurs, then report the exception.
         auto result = callback->invoke(deadline_arg);
         if (result.is_error())
@@ -730,11 +720,11 @@ Vector<JS::NonnullGCPtr<Plugin>> Window::pdf_viewer_plugin_objects()
 
     if (m_pdf_viewer_plugin_objects.is_empty()) {
         // FIXME: Propagate errors.
-        m_pdf_viewer_plugin_objects.append(realm().heap().allocate<Plugin>(realm(), realm(), "PDF Viewer"_string).release_allocated_value_but_fixme_should_propagate_errors());
-        m_pdf_viewer_plugin_objects.append(realm().heap().allocate<Plugin>(realm(), realm(), "Chrome PDF Viewer"_string).release_allocated_value_but_fixme_should_propagate_errors());
-        m_pdf_viewer_plugin_objects.append(realm().heap().allocate<Plugin>(realm(), realm(), "Chromium PDF Viewer"_string).release_allocated_value_but_fixme_should_propagate_errors());
-        m_pdf_viewer_plugin_objects.append(realm().heap().allocate<Plugin>(realm(), realm(), "Microsoft Edge PDF Viewer"_string).release_allocated_value_but_fixme_should_propagate_errors());
-        m_pdf_viewer_plugin_objects.append(realm().heap().allocate<Plugin>(realm(), realm(), "WebKit built-in PDF"_string).release_allocated_value_but_fixme_should_propagate_errors());
+        m_pdf_viewer_plugin_objects.append(realm().heap().allocate<Plugin>(realm(), realm(), "PDF Viewer"_string));
+        m_pdf_viewer_plugin_objects.append(realm().heap().allocate<Plugin>(realm(), realm(), "Chrome PDF Viewer"_string));
+        m_pdf_viewer_plugin_objects.append(realm().heap().allocate<Plugin>(realm(), realm(), "Chromium PDF Viewer"_string));
+        m_pdf_viewer_plugin_objects.append(realm().heap().allocate<Plugin>(realm(), realm(), "Microsoft Edge PDF Viewer"_string));
+        m_pdf_viewer_plugin_objects.append(realm().heap().allocate<Plugin>(realm(), realm(), "WebKit built-in PDF"_string));
     }
 
     return m_pdf_viewer_plugin_objects;
@@ -753,8 +743,8 @@ Vector<JS::NonnullGCPtr<MimeType>> Window::pdf_viewer_mime_type_objects()
         return {};
 
     if (m_pdf_viewer_mime_type_objects.is_empty()) {
-        m_pdf_viewer_mime_type_objects.append(realm().heap().allocate<MimeType>(realm(), realm(), "application/pdf"_string).release_allocated_value_but_fixme_should_propagate_errors());
-        m_pdf_viewer_mime_type_objects.append(realm().heap().allocate<MimeType>(realm(), realm(), "text/pdf"_string).release_allocated_value_but_fixme_should_propagate_errors());
+        m_pdf_viewer_mime_type_objects.append(realm().heap().allocate<MimeType>(realm(), realm(), "application/pdf"_string));
+        m_pdf_viewer_mime_type_objects.append(realm().heap().allocate<MimeType>(realm(), realm(), "text/pdf"_string));
     }
 
     return m_pdf_viewer_mime_type_objects;
@@ -776,7 +766,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<WebIDL::CallbackType>> Window::count_queuin
         auto function = JS::NativeFunction::create(realm, move(steps), 0, "size", &realm);
 
         // 3. Set globalObject’s count queuing strategy size function to a Function that represents a reference to F, with callback context equal to globalObject’s relevant settings object.
-        m_count_queuing_strategy_size_function = MUST_OR_THROW_OOM(heap().allocate<WebIDL::CallbackType>(realm, *function, relevant_settings_object(*this)));
+        m_count_queuing_strategy_size_function = heap().allocate<WebIDL::CallbackType>(realm, *function, relevant_settings_object(*this));
     }
 
     return JS::NonnullGCPtr { *m_count_queuing_strategy_size_function };
@@ -800,7 +790,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<WebIDL::CallbackType>> Window::byte_length_
         auto function = JS::NativeFunction::create(realm, move(steps), 1, "size", &realm);
 
         // 3. Set globalObject’s byte length queuing strategy size function to a Function that represents a reference to F, with callback context equal to globalObject’s relevant settings object.
-        m_byte_length_queuing_strategy_size_function = MUST_OR_THROW_OOM(heap().allocate<WebIDL::CallbackType>(realm, *function, relevant_settings_object(*this)));
+        m_byte_length_queuing_strategy_size_function = heap().allocate<WebIDL::CallbackType>(realm, *function, relevant_settings_object(*this));
     }
 
     return JS::NonnullGCPtr { *m_byte_length_queuing_strategy_size_function };
@@ -824,7 +814,7 @@ WebIDL::ExceptionOr<void> Window::initialize_web_interfaces(Badge<WindowEnvironm
     WindowOrWorkerGlobalScopeMixin::initialize(realm);
 
     if (s_internals_object_exposed)
-        define_direct_property("internals", MUST_OR_THROW_OOM(heap().allocate<Internals::Internals>(realm, realm)), JS::default_attributes);
+        define_direct_property("internals", heap().allocate<Internals::Internals>(realm, realm), JS::default_attributes);
 
     return {};
 }
@@ -880,13 +870,13 @@ void Window::set_name(String const& name)
 }
 
 // https://html.spec.whatwg.org/multipage/nav-history-apis.html#dom-location
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Location>> Window::location()
+JS::NonnullGCPtr<Location> Window::location()
 {
     auto& realm = this->realm();
 
     // The Window object's location getter steps are to return this's Location object.
     if (!m_location)
-        m_location = MUST_OR_THROW_OOM(heap().allocate<Location>(realm, realm));
+        m_location = heap().allocate<Location>(realm, realm);
     return JS::NonnullGCPtr { *m_location };
 }
 
@@ -993,13 +983,13 @@ WebIDL::ExceptionOr<JS::GCPtr<WindowProxy>> Window::open(Optional<String> const&
 }
 
 // https://html.spec.whatwg.org/multipage/system-state.html#dom-navigator
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Navigator>> Window::navigator()
+JS::NonnullGCPtr<Navigator> Window::navigator()
 {
     auto& realm = this->realm();
 
     // The navigator and clientInformation getter steps are to return this's associated Navigator.
     if (!m_navigator)
-        m_navigator = MUST_OR_THROW_OOM(heap().allocate<Navigator>(realm, realm));
+        m_navigator = heap().allocate<Navigator>(realm, realm);
     return JS::NonnullGCPtr { *m_navigator };
 }
 
@@ -1043,7 +1033,7 @@ void Window::post_message(JS::Value message, String const&)
         MessageEventInit event_init {};
         event_init.data = message;
         event_init.origin = "<origin>"_string;
-        dispatch_event(MessageEvent::create(realm(), EventNames::message, event_init).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(MessageEvent::create(realm(), EventNames::message, event_init));
     });
 }
 
@@ -1057,11 +1047,11 @@ Variant<JS::Handle<DOM::Event>, JS::Value> Window::event() const
 }
 
 // https://w3c.github.io/csswg-drafts/cssom/#dom-window-getcomputedstyle
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSS::CSSStyleDeclaration>> Window::get_computed_style(DOM::Element& element, Optional<String> const& pseudo_element) const
+JS::NonnullGCPtr<CSS::CSSStyleDeclaration> Window::get_computed_style(DOM::Element& element, Optional<String> const& pseudo_element) const
 {
     // FIXME: Make this fully spec compliant.
     (void)pseudo_element;
-    return MUST_OR_THROW_OOM(heap().allocate<CSS::ResolvedCSSStyleDeclaration>(realm(), element));
+    return heap().allocate<CSS::ResolvedCSSStyleDeclaration>(realm(), element);
 }
 
 // https://w3c.github.io/csswg-drafts/cssom-view/#dom-window-matchmedia
@@ -1071,21 +1061,21 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<CSS::MediaQueryList>> Window::match_media(S
     auto parsed_media_query_list = parse_media_query_list(CSS::Parser::ParsingContext(associated_document()), query);
 
     // 2. Return a new MediaQueryList object, with this's associated Document as the document, with parsed media query list as its associated media query list.
-    auto media_query_list = MUST_OR_THROW_OOM(heap().allocate<CSS::MediaQueryList>(realm(), associated_document(), move(parsed_media_query_list)));
+    auto media_query_list = heap().allocate<CSS::MediaQueryList>(realm(), associated_document(), move(parsed_media_query_list));
     associated_document().add_media_query_list(media_query_list);
     return media_query_list;
 }
 
 // https://w3c.github.io/csswg-drafts/cssom-view/#dom-window-screen
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CSS::Screen>> Window::screen()
+JS::NonnullGCPtr<CSS::Screen> Window::screen()
 {
     // The screen attribute must return the Screen object associated with the Window object.
     if (!m_screen)
-        m_screen = MUST_OR_THROW_OOM(heap().allocate<CSS::Screen>(realm(), *this));
+        m_screen = heap().allocate<CSS::Screen>(realm(), *this);
     return JS::NonnullGCPtr { *m_screen };
 }
 
-WebIDL::ExceptionOr<JS::GCPtr<CSS::VisualViewport>> Window::visual_viewport()
+JS::GCPtr<CSS::VisualViewport> Window::visual_viewport()
 {
     // If the associated document is fully active, the visualViewport attribute must return
     // the VisualViewport object associated with the Window object’s associated document.
@@ -1396,31 +1386,31 @@ JS::GCPtr<Selection::Selection> Window::get_selection() const
 }
 
 // https://w3c.github.io/hr-time/#dom-windoworworkerglobalscope-performance
-WebIDL::ExceptionOr<JS::NonnullGCPtr<HighResolutionTime::Performance>> Window::performance()
+JS::NonnullGCPtr<HighResolutionTime::Performance> Window::performance()
 {
     if (!m_performance)
-        m_performance = MUST_OR_THROW_OOM(heap().allocate<HighResolutionTime::Performance>(realm(), *this));
+        m_performance = heap().allocate<HighResolutionTime::Performance>(realm(), *this);
     return JS::NonnullGCPtr { *m_performance };
 }
 
 // https://w3c.github.io/webcrypto/#dom-windoworworkerglobalscope-crypto
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Crypto::Crypto>> Window::crypto()
+JS::NonnullGCPtr<Crypto::Crypto> Window::crypto()
 {
     auto& realm = this->realm();
 
     if (!m_crypto)
-        m_crypto = MUST_OR_THROW_OOM(heap().allocate<Crypto::Crypto>(realm, realm));
+        m_crypto = heap().allocate<Crypto::Crypto>(realm, realm);
     return JS::NonnullGCPtr { *m_crypto };
 }
 
 // https://html.spec.whatwg.org/multipage/custom-elements.html#dom-window-customelements
-WebIDL::ExceptionOr<JS::NonnullGCPtr<CustomElementRegistry>> Window::custom_elements()
+JS::NonnullGCPtr<CustomElementRegistry> Window::custom_elements()
 {
     auto& realm = this->realm();
 
     // The customElements attribute of the Window interface must return the CustomElementRegistry object for that Window object.
     if (!m_custom_element_registry)
-        m_custom_element_registry = MUST_OR_THROW_OOM(heap().allocate<CustomElementRegistry>(realm, realm));
+        m_custom_element_registry = heap().allocate<CustomElementRegistry>(realm, realm);
     return JS::NonnullGCPtr { *m_custom_element_registry };
 }
 
diff --git a/Userland/Libraries/LibWeb/HTML/Window.h b/Userland/Libraries/LibWeb/HTML/Window.h
index 9b0452165c2..5f5f12baed5 100644
--- a/Userland/Libraries/LibWeb/HTML/Window.h
+++ b/Userland/Libraries/LibWeb/HTML/Window.h
@@ -46,7 +46,7 @@ class Window final
     WEB_PLATFORM_OBJECT(Window, DOM::EventTarget);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Window>> create(JS::Realm&);
+    [[nodiscard]] static JS::NonnullGCPtr<Window> create(JS::Realm&);
 
     ~Window();
 
@@ -131,7 +131,7 @@ public:
     JS::NonnullGCPtr<DOM::Document const> document() const;
     String name() const;
     void set_name(String const&);
-    WebIDL::ExceptionOr<JS::NonnullGCPtr<Location>> location();
+    [[nodiscard]] JS::NonnullGCPtr<Location> location();
     JS::NonnullGCPtr<History> history() const;
     void focus();
 
@@ -142,7 +142,7 @@ public:
     JS::GCPtr<DOM::Element const> frame_element() const;
     WebIDL::ExceptionOr<JS::GCPtr<WindowProxy>> open(Optional<String> const& url, Optional<String> const& target, Optional<String> const& features);
 
-    WebIDL::ExceptionOr<JS::NonnullGCPtr<Navigator>> navigator();
+    [[nodiscard]] JS::NonnullGCPtr<Navigator> navigator();
 
     void alert(String const& message = {});
     bool confirm(Optional<String> const& message);
@@ -152,11 +152,11 @@ public:
 
     Variant<JS::Handle<DOM::Event>, JS::Value> event() const;
 
-    WebIDL::ExceptionOr<JS::NonnullGCPtr<CSS::CSSStyleDeclaration>> get_computed_style(DOM::Element&, Optional<String> const& pseudo_element) const;
+    [[nodiscard]] JS::NonnullGCPtr<CSS::CSSStyleDeclaration> get_computed_style(DOM::Element&, Optional<String> const& pseudo_element) const;
 
     WebIDL::ExceptionOr<JS::NonnullGCPtr<CSS::MediaQueryList>> match_media(String const& query);
-    WebIDL::ExceptionOr<JS::NonnullGCPtr<CSS::Screen>> screen();
-    WebIDL::ExceptionOr<JS::GCPtr<CSS::VisualViewport>> visual_viewport();
+    [[nodiscard]] JS::NonnullGCPtr<CSS::Screen> screen();
+    [[nodiscard]] JS::GCPtr<CSS::VisualViewport> visual_viewport();
 
     i32 inner_width() const;
     i32 inner_height() const;
@@ -182,11 +182,11 @@ public:
 
     JS::GCPtr<Selection::Selection> get_selection() const;
 
-    WebIDL::ExceptionOr<JS::NonnullGCPtr<HighResolutionTime::Performance>> performance();
+    [[nodiscard]] JS::NonnullGCPtr<HighResolutionTime::Performance> performance();
 
-    WebIDL::ExceptionOr<JS::NonnullGCPtr<Crypto::Crypto>> crypto();
+    [[nodiscard]] JS::NonnullGCPtr<Crypto::Crypto> crypto();
 
-    WebIDL::ExceptionOr<JS::NonnullGCPtr<CustomElementRegistry>> custom_elements();
+    [[nodiscard]] JS::NonnullGCPtr<CustomElementRegistry> custom_elements();
 
     HighResolutionTime::DOMHighResTimeStamp get_last_activation_timestamp() const { return m_last_activation_timestamp; }
     void set_last_activation_timestamp(HighResolutionTime::DOMHighResTimeStamp timestamp) { m_last_activation_timestamp = timestamp; }
diff --git a/Userland/Libraries/LibWeb/HTML/Worker.cpp b/Userland/Libraries/LibWeb/HTML/Worker.cpp
index 6f9f2f87a01..1662fedb5fb 100644
--- a/Userland/Libraries/LibWeb/HTML/Worker.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Worker.cpp
@@ -23,7 +23,7 @@ Worker::Worker(String const& script_url, WorkerOptions const options, DOM::Docum
     , m_document(&document)
     , m_custom_data()
     , m_worker_vm(JS::VM::create(adopt_own(m_custom_data)).release_value_but_fixme_should_propagate_errors())
-    , m_implicit_port(MessagePort::create(document.realm()).release_value_but_fixme_should_propagate_errors())
+    , m_implicit_port(MessagePort::create(document.realm()))
 {
 }
 
@@ -77,10 +77,10 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Worker>> Worker::create(String const& scrip
     // 5. Let worker URL be the resulting URL record.
 
     // 6. Let worker be a new Worker object.
-    auto worker = MUST_OR_THROW_OOM(document.heap().allocate<Worker>(document.realm(), script_url, options, document));
+    auto worker = document.heap().allocate<Worker>(document.realm(), script_url, options, document);
 
     // 7. Let outside port be a new MessagePort in outside settings's Realm.
-    auto outside_port = TRY(MessagePort::create(outside_settings.realm()));
+    auto outside_port = MessagePort::create(outside_settings.realm());
 
     // 8. Associate the outside port with worker
     worker->m_outside_port = outside_port;
@@ -166,7 +166,7 @@ void Worker::run_a_worker(AK::URL& url, EnvironmentSettingsObject& outside_setti
                 MessageEventInit event_init {};
                 event_init.data = message;
                 event_init.origin = "<origin>"_string;
-                dispatch_event(MessageEvent::create(*m_worker_realm, HTML::EventNames::message, event_init).release_value_but_fixme_should_propagate_errors());
+                dispatch_event(MessageEvent::create(*m_worker_realm, HTML::EventNames::message, event_init));
             }));
 
             return JS::js_undefined();
@@ -263,7 +263,7 @@ void Worker::run_a_worker(AK::URL& url, EnvironmentSettingsObject& outside_setti
             // FIXME: Global scope association
 
             // 16. Let inside port be a new MessagePort object in inside settings's Realm.
-            auto inside_port = MessagePort::create(m_inner_settings->realm()).release_value_but_fixme_should_propagate_errors();
+            auto inside_port = MessagePort::create(m_inner_settings->realm());
 
             // 17. Associate inside port with worker global scope.
             // FIXME: Global scope association
diff --git a/Userland/Libraries/LibWeb/HTML/WorkerGlobalScope.cpp b/Userland/Libraries/LibWeb/HTML/WorkerGlobalScope.cpp
index 620b05043f6..3811f34e71a 100644
--- a/Userland/Libraries/LibWeb/HTML/WorkerGlobalScope.cpp
+++ b/Userland/Libraries/LibWeb/HTML/WorkerGlobalScope.cpp
@@ -27,7 +27,7 @@ WorkerGlobalScope::~WorkerGlobalScope() = default;
 void WorkerGlobalScope::initialize(JS::Realm& realm)
 {
     Base::initialize(realm);
-    m_navigator = MUST(WorkerNavigator::create(*this));
+    m_navigator = WorkerNavigator::create(*this);
 }
 
 void WorkerGlobalScope::visit_edges(Cell::Visitor& visitor)
diff --git a/Userland/Libraries/LibWeb/HTML/WorkerNavigator.cpp b/Userland/Libraries/LibWeb/HTML/WorkerNavigator.cpp
index bb6add43c84..2585f260b46 100644
--- a/Userland/Libraries/LibWeb/HTML/WorkerNavigator.cpp
+++ b/Userland/Libraries/LibWeb/HTML/WorkerNavigator.cpp
@@ -11,9 +11,9 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<WorkerNavigator>> WorkerNavigator::create(WorkerGlobalScope& global_scope)
+JS::NonnullGCPtr<WorkerNavigator> WorkerNavigator::create(WorkerGlobalScope& global_scope)
 {
-    return MUST_OR_THROW_OOM(global_scope.heap().allocate<WorkerNavigator>(global_scope.realm(), global_scope));
+    return global_scope.heap().allocate<WorkerNavigator>(global_scope.realm(), global_scope);
 }
 
 WorkerNavigator::WorkerNavigator(WorkerGlobalScope& global_scope)
diff --git a/Userland/Libraries/LibWeb/HTML/WorkerNavigator.h b/Userland/Libraries/LibWeb/HTML/WorkerNavigator.h
index efc18d79df7..d5e73cb22e1 100644
--- a/Userland/Libraries/LibWeb/HTML/WorkerNavigator.h
+++ b/Userland/Libraries/LibWeb/HTML/WorkerNavigator.h
@@ -22,7 +22,7 @@ class WorkerNavigator : public Bindings::PlatformObject
     WEB_PLATFORM_OBJECT(WorkerNavigator, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<WorkerNavigator>> create(WorkerGlobalScope&);
+    [[nodiscard]] static JS::NonnullGCPtr<WorkerNavigator> create(WorkerGlobalScope&);
 
     virtual ~WorkerNavigator() override;
 
diff --git a/Userland/Libraries/LibWeb/HighResolutionTime/Performance.cpp b/Userland/Libraries/LibWeb/HighResolutionTime/Performance.cpp
index e1b638fb2f7..f1fad3b3946 100644
--- a/Userland/Libraries/LibWeb/HighResolutionTime/Performance.cpp
+++ b/Userland/Libraries/LibWeb/HighResolutionTime/Performance.cpp
@@ -43,7 +43,7 @@ void Performance::visit_edges(Cell::Visitor& visitor)
 JS::GCPtr<NavigationTiming::PerformanceTiming> Performance::timing()
 {
     if (!m_timing)
-        m_timing = heap().allocate<NavigationTiming::PerformanceTiming>(realm(), *m_window).release_allocated_value_but_fixme_should_propagate_errors();
+        m_timing = heap().allocate<NavigationTiming::PerformanceTiming>(realm(), *m_window);
     return m_timing;
 }
 
@@ -290,7 +290,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<UserTiming::PerformanceMeasure>> Performanc
     // NOTE: Already the default value of `detail`.
 
     // 4. Create a new PerformanceMeasure object (entry) with this's relevant realm.
-    auto entry = MUST_OR_THROW_OOM(realm.heap().allocate<UserTiming::PerformanceMeasure>(realm, realm, measure_name, start_time, duration, detail));
+    auto entry = realm.heap().allocate<UserTiming::PerformanceMeasure>(realm, realm, measure_name, start_time, duration, detail);
 
     // 10. Queue entry.
     TRY(window_or_worker->queue_performance_entry(entry));
diff --git a/Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.cpp b/Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.cpp
index f4d7b2242ba..e7031ecce0d 100644
--- a/Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.cpp
+++ b/Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.cpp
@@ -39,7 +39,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<IntersectionObserver>> IntersectionObserver
     // 2. Set this’s internal [[callback]] slot to callback.
     // 8. The thresholds attribute getter will return this sorted thresholds list.
     // 9. Return this.
-    return MUST_OR_THROW_OOM(realm.heap().allocate<IntersectionObserver>(realm, realm, callback, options.root, move(thresholds)));
+    return realm.heap().allocate<IntersectionObserver>(realm, realm, callback, options.root, move(thresholds));
 }
 
 IntersectionObserver::IntersectionObserver(JS::Realm& realm, JS::GCPtr<WebIDL::CallbackType> callback, Optional<Variant<JS::Handle<DOM::Element>, JS::Handle<DOM::Document>>> const& root, Vector<double>&& thresholds)
diff --git a/Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserverEntry.cpp b/Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserverEntry.cpp
index 645d5eb165d..e24bdd6ac0d 100644
--- a/Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserverEntry.cpp
+++ b/Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserverEntry.cpp
@@ -16,11 +16,11 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<IntersectionObserverEntry>> IntersectionObs
 
     JS::GCPtr<Geometry::DOMRectReadOnly> root_bounds;
     if (options.root_bounds.has_value())
-        root_bounds = TRY(Geometry::DOMRectReadOnly::from_rect(vm, options.root_bounds.value()));
+        root_bounds = Geometry::DOMRectReadOnly::from_rect(vm, options.root_bounds.value());
 
-    auto bounding_client_rect = TRY(Geometry::DOMRectReadOnly::from_rect(vm, options.bounding_client_rect));
-    auto intersection_rect = TRY(Geometry::DOMRectReadOnly::from_rect(vm, options.intersection_rect));
-    return MUST_OR_THROW_OOM(realm.heap().allocate<IntersectionObserverEntry>(realm, realm, options.time, root_bounds, bounding_client_rect, intersection_rect, options.is_intersecting, options.intersection_ratio, *options.target));
+    auto bounding_client_rect = Geometry::DOMRectReadOnly::from_rect(vm, options.bounding_client_rect);
+    auto intersection_rect = Geometry::DOMRectReadOnly::from_rect(vm, options.intersection_rect);
+    return realm.heap().allocate<IntersectionObserverEntry>(realm, realm, options.time, root_bounds, bounding_client_rect, intersection_rect, options.is_intersecting, options.intersection_ratio, *options.target);
 }
 
 IntersectionObserverEntry::IntersectionObserverEntry(JS::Realm& realm, HighResolutionTime::DOMHighResTimeStamp time, JS::GCPtr<Geometry::DOMRectReadOnly> root_bounds, JS::NonnullGCPtr<Geometry::DOMRectReadOnly> bounding_client_rect, JS::NonnullGCPtr<Geometry::DOMRectReadOnly> intersection_rect, bool is_intersecting, double intersection_ratio, JS::NonnullGCPtr<DOM::Element> target)
diff --git a/Userland/Libraries/LibWeb/Layout/TreeBuilder.cpp b/Userland/Libraries/LibWeb/Layout/TreeBuilder.cpp
index 83ea5cea6f2..46ad7633ea5 100644
--- a/Userland/Libraries/LibWeb/Layout/TreeBuilder.cpp
+++ b/Userland/Libraries/LibWeb/Layout/TreeBuilder.cpp
@@ -203,7 +203,7 @@ ErrorOr<void> TreeBuilder::create_pseudo_element_if_needed(DOM::Element& element
 
     // FIXME: Handle images, and multiple values
     if (pseudo_element_content.type == CSS::ContentData::Type::String) {
-        auto text = document.heap().allocate<DOM::Text>(document.realm(), document, pseudo_element_content.data.to_deprecated_string()).release_allocated_value_but_fixme_should_propagate_errors();
+        auto text = document.heap().allocate<DOM::Text>(document.realm(), document, pseudo_element_content.data.to_deprecated_string());
         auto text_node = document.heap().allocate_without_realm<Layout::TextNode>(document, *text);
         text_node->set_generated_for(generated_for, element);
 
diff --git a/Userland/Libraries/LibWeb/MathML/MathMLElement.cpp b/Userland/Libraries/LibWeb/MathML/MathMLElement.cpp
index cafa20d34e0..16fcac25ed3 100644
--- a/Userland/Libraries/LibWeb/MathML/MathMLElement.cpp
+++ b/Userland/Libraries/LibWeb/MathML/MathMLElement.cpp
@@ -22,7 +22,7 @@ void MathMLElement::initialize(JS::Realm& realm)
     Base::initialize(realm);
     set_prototype(&Bindings::ensure_web_prototype<Bindings::MathMLElementPrototype>(realm, "MathMLElement"));
 
-    m_dataset = MUST(HTML::DOMStringMap::create(*this));
+    m_dataset = HTML::DOMStringMap::create(*this);
 }
 
 Optional<ARIA::Role> MathMLElement::default_role() const
diff --git a/Userland/Libraries/LibWeb/Page/EventHandler.cpp b/Userland/Libraries/LibWeb/Page/EventHandler.cpp
index 57e25fb5be8..7d712364e0c 100644
--- a/Userland/Libraries/LibWeb/Page/EventHandler.cpp
+++ b/Userland/Libraries/LibWeb/Page/EventHandler.cpp
@@ -693,12 +693,12 @@ bool EventHandler::fire_keyboard_event(FlyString const& event_name, HTML::Browsi
                 return fire_keyboard_event(event_name, *navigable_container.nested_browsing_context(), key, modifiers, code_point);
         }
 
-        auto event = UIEvents::KeyboardEvent::create_from_platform_event(document->realm(), event_name, key, modifiers, code_point).release_value_but_fixme_should_propagate_errors();
+        auto event = UIEvents::KeyboardEvent::create_from_platform_event(document->realm(), event_name, key, modifiers, code_point);
         return !focused_element->dispatch_event(event);
     }
 
     // FIXME: De-duplicate this. This is just to prevent wasting a KeyboardEvent allocation when recursing into an (i)frame.
-    auto event = UIEvents::KeyboardEvent::create_from_platform_event(document->realm(), event_name, key, modifiers, code_point).release_value_but_fixme_should_propagate_errors();
+    auto event = UIEvents::KeyboardEvent::create_from_platform_event(document->realm(), event_name, key, modifiers, code_point);
 
     if (JS::GCPtr<HTML::HTMLElement> body = document->body())
         return !body->dispatch_event(event);
diff --git a/Userland/Libraries/LibWeb/RequestIdleCallback/IdleDeadline.cpp b/Userland/Libraries/LibWeb/RequestIdleCallback/IdleDeadline.cpp
index b4641bcd4f4..b0d6fb123d0 100644
--- a/Userland/Libraries/LibWeb/RequestIdleCallback/IdleDeadline.cpp
+++ b/Userland/Libraries/LibWeb/RequestIdleCallback/IdleDeadline.cpp
@@ -12,9 +12,9 @@
 
 namespace Web::RequestIdleCallback {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<IdleDeadline>> IdleDeadline::create(JS::Realm& realm, bool did_timeout)
+JS::NonnullGCPtr<IdleDeadline> IdleDeadline::create(JS::Realm& realm, bool did_timeout)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<IdleDeadline>(realm, realm, did_timeout));
+    return realm.heap().allocate<IdleDeadline>(realm, realm, did_timeout);
 }
 
 IdleDeadline::IdleDeadline(JS::Realm& realm, bool did_timeout)
diff --git a/Userland/Libraries/LibWeb/RequestIdleCallback/IdleDeadline.h b/Userland/Libraries/LibWeb/RequestIdleCallback/IdleDeadline.h
index 1a150ca111f..3776599c6db 100644
--- a/Userland/Libraries/LibWeb/RequestIdleCallback/IdleDeadline.h
+++ b/Userland/Libraries/LibWeb/RequestIdleCallback/IdleDeadline.h
@@ -15,7 +15,7 @@ class IdleDeadline final : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(IdleDeadline, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<IdleDeadline>> create(JS::Realm&, bool did_timeout = false);
+    [[nodiscard]] static JS::NonnullGCPtr<IdleDeadline> create(JS::Realm&, bool did_timeout = false);
     virtual ~IdleDeadline() override;
 
     double time_remaining() const;
diff --git a/Userland/Libraries/LibWeb/ResizeObserver/ResizeObserver.cpp b/Userland/Libraries/LibWeb/ResizeObserver/ResizeObserver.cpp
index 3655f502f37..3c8473c0bf2 100644
--- a/Userland/Libraries/LibWeb/ResizeObserver/ResizeObserver.cpp
+++ b/Userland/Libraries/LibWeb/ResizeObserver/ResizeObserver.cpp
@@ -15,7 +15,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<ResizeObserver>> ResizeObserver::construct_
 {
     // FIXME: Implement
     (void)callback;
-    return MUST_OR_THROW_OOM(realm.heap().allocate<ResizeObserver>(realm, realm));
+    return realm.heap().allocate<ResizeObserver>(realm, realm);
 }
 
 ResizeObserver::ResizeObserver(JS::Realm& realm)
diff --git a/Userland/Libraries/LibWeb/SVG/SVGAnimatedLength.cpp b/Userland/Libraries/LibWeb/SVG/SVGAnimatedLength.cpp
index 6943ed17106..124e2ed9609 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGAnimatedLength.cpp
+++ b/Userland/Libraries/LibWeb/SVG/SVGAnimatedLength.cpp
@@ -9,9 +9,9 @@
 
 namespace Web::SVG {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<SVGAnimatedLength>> SVGAnimatedLength::create(JS::Realm& realm, JS::NonnullGCPtr<SVGLength> base_val, JS::NonnullGCPtr<SVGLength> anim_val)
+JS::NonnullGCPtr<SVGAnimatedLength> SVGAnimatedLength::create(JS::Realm& realm, JS::NonnullGCPtr<SVGLength> base_val, JS::NonnullGCPtr<SVGLength> anim_val)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<SVGAnimatedLength>(realm, realm, move(base_val), move(anim_val)));
+    return realm.heap().allocate<SVGAnimatedLength>(realm, realm, move(base_val), move(anim_val));
 }
 
 SVGAnimatedLength::SVGAnimatedLength(JS::Realm& realm, JS::NonnullGCPtr<SVGLength> base_val, JS::NonnullGCPtr<SVGLength> anim_val)
diff --git a/Userland/Libraries/LibWeb/SVG/SVGAnimatedLength.h b/Userland/Libraries/LibWeb/SVG/SVGAnimatedLength.h
index a1255f52bf8..5aab8e6c1cb 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGAnimatedLength.h
+++ b/Userland/Libraries/LibWeb/SVG/SVGAnimatedLength.h
@@ -16,7 +16,7 @@ class SVGAnimatedLength final : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(SVGAnimatedLength, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<SVGAnimatedLength>> create(JS::Realm&, JS::NonnullGCPtr<SVGLength> base_val, JS::NonnullGCPtr<SVGLength> anim_val);
+    [[nodiscard]] static JS::NonnullGCPtr<SVGAnimatedLength> create(JS::Realm&, JS::NonnullGCPtr<SVGLength> base_val, JS::NonnullGCPtr<SVGLength> anim_val);
     virtual ~SVGAnimatedLength() override;
 
     JS::NonnullGCPtr<SVGLength> base_val() const { return m_base_val; }
diff --git a/Userland/Libraries/LibWeb/SVG/SVGAnimatedNumber.cpp b/Userland/Libraries/LibWeb/SVG/SVGAnimatedNumber.cpp
index 18ec1ab3a1d..6304096fba9 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGAnimatedNumber.cpp
+++ b/Userland/Libraries/LibWeb/SVG/SVGAnimatedNumber.cpp
@@ -9,9 +9,9 @@
 
 namespace Web::SVG {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<SVGAnimatedNumber>> SVGAnimatedNumber::create(JS::Realm& realm, float base_val, float anim_val)
+JS::NonnullGCPtr<SVGAnimatedNumber> SVGAnimatedNumber::create(JS::Realm& realm, float base_val, float anim_val)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<SVGAnimatedNumber>(realm, realm, base_val, anim_val));
+    return realm.heap().allocate<SVGAnimatedNumber>(realm, realm, base_val, anim_val);
 }
 
 SVGAnimatedNumber::SVGAnimatedNumber(JS::Realm& realm, float base_val, float anim_val)
diff --git a/Userland/Libraries/LibWeb/SVG/SVGAnimatedNumber.h b/Userland/Libraries/LibWeb/SVG/SVGAnimatedNumber.h
index a9e09af7e2f..b08aa94331c 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGAnimatedNumber.h
+++ b/Userland/Libraries/LibWeb/SVG/SVGAnimatedNumber.h
@@ -16,7 +16,7 @@ class SVGAnimatedNumber final : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(SVGAnimatedNumber, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<SVGAnimatedNumber>> create(JS::Realm&, float base_val, float anim_val);
+    [[nodiscard]] static JS::NonnullGCPtr<SVGAnimatedNumber> create(JS::Realm&, float base_val, float anim_val);
     virtual ~SVGAnimatedNumber() override;
 
     float base_val() const { return m_base_val; }
diff --git a/Userland/Libraries/LibWeb/SVG/SVGCircleElement.cpp b/Userland/Libraries/LibWeb/SVG/SVGCircleElement.cpp
index 534d677edfd..b5786256962 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGCircleElement.cpp
+++ b/Userland/Libraries/LibWeb/SVG/SVGCircleElement.cpp
@@ -82,9 +82,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGCircleElement::cx() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_center_x.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_center_x.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_center_x.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_center_x.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#CircleElementCYAttribute
@@ -92,9 +92,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGCircleElement::cy() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_center_y.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_center_y.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_center_y.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_center_y.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#CircleElementRAttribute
@@ -102,9 +102,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGCircleElement::r() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_radius.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_radius.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_radius.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_radius.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 }
diff --git a/Userland/Libraries/LibWeb/SVG/SVGElement.cpp b/Userland/Libraries/LibWeb/SVG/SVGElement.cpp
index d35b6bb9c7d..e04301bd4c1 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGElement.cpp
+++ b/Userland/Libraries/LibWeb/SVG/SVGElement.cpp
@@ -25,7 +25,7 @@ void SVGElement::initialize(JS::Realm& realm)
     Base::initialize(realm);
     set_prototype(&Bindings::ensure_web_prototype<Bindings::SVGElementPrototype>(realm, "SVGElement"));
 
-    m_dataset = MUST(HTML::DOMStringMap::create(*this));
+    m_dataset = HTML::DOMStringMap::create(*this);
 }
 
 void SVGElement::visit_edges(Cell::Visitor& visitor)
diff --git a/Userland/Libraries/LibWeb/SVG/SVGEllipseElement.cpp b/Userland/Libraries/LibWeb/SVG/SVGEllipseElement.cpp
index c519fce6925..fb8c1b3b55b 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGEllipseElement.cpp
+++ b/Userland/Libraries/LibWeb/SVG/SVGEllipseElement.cpp
@@ -87,9 +87,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGEllipseElement::cx() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_center_x.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_center_x.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_center_x.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_center_x.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#EllipseElementCYAttribute
@@ -97,9 +97,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGEllipseElement::cy() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_center_y.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_center_y.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_center_y.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_center_y.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#EllipseElementRXAttribute
@@ -107,9 +107,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGEllipseElement::rx() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_radius_x.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_radius_x.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_radius_x.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_radius_x.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#EllipseElementRYAttribute
@@ -117,9 +117,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGEllipseElement::ry() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_radius_y.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_radius_y.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_radius_y.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_radius_y.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 }
diff --git a/Userland/Libraries/LibWeb/SVG/SVGForeignObjectElement.cpp b/Userland/Libraries/LibWeb/SVG/SVGForeignObjectElement.cpp
index 2f259bf24ee..af4de78c489 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGForeignObjectElement.cpp
+++ b/Userland/Libraries/LibWeb/SVG/SVGForeignObjectElement.cpp
@@ -28,10 +28,10 @@ void SVGForeignObjectElement::initialize(JS::Realm& realm)
     set_prototype(&Bindings::ensure_web_prototype<Bindings::SVGForeignObjectElementPrototype>(realm, "SVGForeignObjectElement"));
 
     // FIXME: These never actually get updated!
-    m_x = MUST(SVGAnimatedLength::create(realm, MUST(SVGLength::create(realm, 0, 0)), MUST(SVGLength::create(realm, 0, 0))));
-    m_y = MUST(SVGAnimatedLength::create(realm, MUST(SVGLength::create(realm, 0, 0)), MUST(SVGLength::create(realm, 0, 0))));
-    m_width = MUST(SVGAnimatedLength::create(realm, MUST(SVGLength::create(realm, 0, 0)), MUST(SVGLength::create(realm, 0, 0))));
-    m_height = MUST(SVGAnimatedLength::create(realm, MUST(SVGLength::create(realm, 0, 0)), MUST(SVGLength::create(realm, 0, 0))));
+    m_x = SVGAnimatedLength::create(realm, SVGLength::create(realm, 0, 0), SVGLength::create(realm, 0, 0));
+    m_y = SVGAnimatedLength::create(realm, SVGLength::create(realm, 0, 0), SVGLength::create(realm, 0, 0));
+    m_width = SVGAnimatedLength::create(realm, SVGLength::create(realm, 0, 0), SVGLength::create(realm, 0, 0));
+    m_height = SVGAnimatedLength::create(realm, SVGLength::create(realm, 0, 0), SVGLength::create(realm, 0, 0));
 }
 
 void SVGForeignObjectElement::visit_edges(Cell::Visitor& visitor)
diff --git a/Userland/Libraries/LibWeb/SVG/SVGLength.cpp b/Userland/Libraries/LibWeb/SVG/SVGLength.cpp
index 1be1227120c..ae53ce61e05 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGLength.cpp
+++ b/Userland/Libraries/LibWeb/SVG/SVGLength.cpp
@@ -9,9 +9,9 @@
 
 namespace Web::SVG {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<SVGLength>> SVGLength::create(JS::Realm& realm, u8 unit_type, float value)
+JS::NonnullGCPtr<SVGLength> SVGLength::create(JS::Realm& realm, u8 unit_type, float value)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<SVGLength>(realm, realm, unit_type, value));
+    return realm.heap().allocate<SVGLength>(realm, realm, unit_type, value);
 }
 
 SVGLength::SVGLength(JS::Realm& realm, u8 unit_type, float value)
diff --git a/Userland/Libraries/LibWeb/SVG/SVGLength.h b/Userland/Libraries/LibWeb/SVG/SVGLength.h
index 048e21e5d7d..832e19216e3 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGLength.h
+++ b/Userland/Libraries/LibWeb/SVG/SVGLength.h
@@ -16,7 +16,7 @@ class SVGLength : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(SVGLength, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<SVGLength>> create(JS::Realm&, u8 unit_type, float value);
+    [[nodiscard]] static JS::NonnullGCPtr<SVGLength> create(JS::Realm&, u8 unit_type, float value);
     virtual ~SVGLength() override;
 
     u8 unit_type() const { return m_unit_type; }
diff --git a/Userland/Libraries/LibWeb/SVG/SVGLineElement.cpp b/Userland/Libraries/LibWeb/SVG/SVGLineElement.cpp
index 1704e1e5220..02514028294 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGLineElement.cpp
+++ b/Userland/Libraries/LibWeb/SVG/SVGLineElement.cpp
@@ -67,9 +67,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGLineElement::x1() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_x1.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_x1.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_x1.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_x1.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#LineElementY1Attribute
@@ -77,9 +77,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGLineElement::y1() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_y1.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_y1.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_y1.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_y1.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#LineElementX2Attribute
@@ -87,9 +87,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGLineElement::x2() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_x2.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_x2.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_x2.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_x2.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#LineElementY2Attribute
@@ -97,9 +97,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGLineElement::y2() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_y2.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_y2.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_y2.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_y2.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 }
diff --git a/Userland/Libraries/LibWeb/SVG/SVGRectElement.cpp b/Userland/Libraries/LibWeb/SVG/SVGRectElement.cpp
index b1559ac8393..baf32a20892 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGRectElement.cpp
+++ b/Userland/Libraries/LibWeb/SVG/SVGRectElement.cpp
@@ -164,9 +164,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGRectElement::x() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_x.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_x.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_x.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_x.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#RectElementYAttribute
@@ -174,9 +174,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGRectElement::y() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_y.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_y.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_y.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_y.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#RectElementWidthAttribute
@@ -184,9 +184,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGRectElement::width() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_width.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_width.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_width.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_width.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#RectElementHeightAttribute
@@ -194,9 +194,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGRectElement::height() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_height.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_height.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_height.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_height.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#RectElementRXAttribute
@@ -204,9 +204,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGRectElement::rx() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_radius_x.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_radius_x.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_radius_x.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_radius_x.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#RectElementRYAttribute
@@ -214,9 +214,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGRectElement::ry() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_radius_y.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_radius_y.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_radius_y.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_radius_y.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 }
diff --git a/Userland/Libraries/LibWeb/SVG/SVGUseElement.cpp b/Userland/Libraries/LibWeb/SVG/SVGUseElement.cpp
index 9aee188ab35..947db7bb1a6 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGUseElement.cpp
+++ b/Userland/Libraries/LibWeb/SVG/SVGUseElement.cpp
@@ -27,12 +27,12 @@ void SVGUseElement::initialize(JS::Realm& realm)
     set_prototype(&Bindings::ensure_web_prototype<Bindings::SVGUseElementPrototype>(realm, "SVGUseElement"));
 
     // The shadow tree is open (inspectable by script), but read-only.
-    auto shadow_root = MUST(heap().allocate<DOM::ShadowRoot>(realm, document(), *this, Bindings::ShadowRootMode::Open));
+    auto shadow_root = heap().allocate<DOM::ShadowRoot>(realm, document(), *this, Bindings::ShadowRootMode::Open);
 
     // The user agent must create a use-element shadow tree whose host is the ‘use’ element itself
     set_shadow_root(shadow_root);
 
-    m_document_observer = MUST(realm.heap().allocate<DOM::DocumentObserver>(realm, realm, document()));
+    m_document_observer = realm.heap().allocate<DOM::DocumentObserver>(realm, realm, document());
     m_document_observer->document_completely_loaded = [this]() {
         clone_element_tree_as_our_shadow_tree(referenced_element());
     };
@@ -136,9 +136,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGUseElement::x() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_x.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_x.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_x.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_x.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 // https://www.w3.org/TR/SVG11/shapes.html#RectElementYAttribute
@@ -146,9 +146,9 @@ JS::NonnullGCPtr<SVGAnimatedLength> SVGUseElement::y() const
 {
     // FIXME: Populate the unit type when it is parsed (0 here is "unknown").
     // FIXME: Create a proper animated value when animations are supported.
-    auto base_length = SVGLength::create(realm(), 0, m_y.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    auto anim_length = SVGLength::create(realm(), 0, m_y.value_or(0)).release_value_but_fixme_should_propagate_errors();
-    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length)).release_value_but_fixme_should_propagate_errors();
+    auto base_length = SVGLength::create(realm(), 0, m_y.value_or(0));
+    auto anim_length = SVGLength::create(realm(), 0, m_y.value_or(0));
+    return SVGAnimatedLength::create(realm(), move(base_length), move(anim_length));
 }
 
 JS::NonnullGCPtr<SVGAnimatedLength> SVGUseElement::width() const
diff --git a/Userland/Libraries/LibWeb/Selection/Selection.cpp b/Userland/Libraries/LibWeb/Selection/Selection.cpp
index 546a3a5381f..72aa62b0e60 100644
--- a/Userland/Libraries/LibWeb/Selection/Selection.cpp
+++ b/Userland/Libraries/LibWeb/Selection/Selection.cpp
@@ -11,9 +11,9 @@
 
 namespace Web::Selection {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<Selection>> Selection::create(JS::NonnullGCPtr<JS::Realm> realm, JS::NonnullGCPtr<DOM::Document> document)
+JS::NonnullGCPtr<Selection> Selection::create(JS::NonnullGCPtr<JS::Realm> realm, JS::NonnullGCPtr<DOM::Document> document)
 {
-    return MUST_OR_THROW_OOM(realm->heap().allocate<Selection>(realm, realm, document));
+    return realm->heap().allocate<Selection>(realm, realm, document);
 }
 
 Selection::Selection(JS::NonnullGCPtr<JS::Realm> realm, JS::NonnullGCPtr<DOM::Document> document)
@@ -185,7 +185,7 @@ WebIDL::ExceptionOr<void> Selection::collapse(JS::GCPtr<DOM::Node> node, unsigne
         return {};
 
     // 4. Otherwise, let newRange be a new range.
-    auto new_range = TRY(DOM::Range::create(*m_document));
+    auto new_range = DOM::Range::create(*m_document);
 
     // 5. Set the start the start and the end of newRange to (node, offset).
     TRY(new_range->set_start(*node, offset));
@@ -212,7 +212,7 @@ WebIDL::ExceptionOr<void> Selection::collapse_to_start()
     }
 
     // 2. Otherwise, it must create a new range
-    auto new_range = TRY(DOM::Range::create(*m_document));
+    auto new_range = DOM::Range::create(*m_document);
 
     // 3. Set the start both its start and end to the start of this's range
     TRY(new_range->set_start(*anchor_node(), m_range->start_offset()));
@@ -232,7 +232,7 @@ WebIDL::ExceptionOr<void> Selection::collapse_to_end()
     }
 
     // 2. Otherwise, it must create a new range
-    auto new_range = TRY(DOM::Range::create(*m_document));
+    auto new_range = DOM::Range::create(*m_document);
 
     // 3. Set the start both its start and end to the start of this's range
     TRY(new_range->set_start(*anchor_node(), m_range->end_offset()));
@@ -264,7 +264,7 @@ WebIDL::ExceptionOr<void> Selection::extend(JS::NonnullGCPtr<DOM::Node> node, un
     auto new_focus_offset = offset;
 
     // 4. Let newRange be a new range.
-    auto new_range = TRY(DOM::Range::create(*m_document));
+    auto new_range = DOM::Range::create(*m_document);
 
     // 5. If node's root is not the same as the this's range's root, set the start newRange's start and end to newFocus.
     if (&node->root() != &m_range->start_container()->root()) {
@@ -313,7 +313,7 @@ WebIDL::ExceptionOr<void> Selection::set_base_and_extent(JS::NonnullGCPtr<DOM::N
     // 3. Let anchor be the boundary point (anchorNode, anchorOffset) and let focus be the boundary point (focusNode, focusOffset).
 
     // 4. Let newRange be a new range.
-    auto new_range = TRY(DOM::Range::create(*m_document));
+    auto new_range = DOM::Range::create(*m_document);
 
     // 5. If anchor is before focus, set the start the newRange's start to anchor and its end to focus. Otherwise, set the start them to focus and anchor respectively.
     auto position_of_anchor_relative_to_focus = DOM::position_of_boundary_point_relative_to_other_boundary_point(anchor_node, anchor_offset, focus_node, focus_offset);
@@ -346,7 +346,7 @@ WebIDL::ExceptionOr<void> Selection::select_all_children(JS::NonnullGCPtr<DOM::N
         return {};
 
     // 2. Let newRange be a new range and childCount be the number of children of node.
-    auto new_range = TRY(DOM::Range::create(*m_document));
+    auto new_range = DOM::Range::create(*m_document);
     auto child_count = node->child_count();
 
     // 3. Set newRange's start to (node, 0).
diff --git a/Userland/Libraries/LibWeb/Selection/Selection.h b/Userland/Libraries/LibWeb/Selection/Selection.h
index 1a3e7214dee..d6586b0258f 100644
--- a/Userland/Libraries/LibWeb/Selection/Selection.h
+++ b/Userland/Libraries/LibWeb/Selection/Selection.h
@@ -15,7 +15,7 @@ class Selection final : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(Selection, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<Selection>> create(JS::NonnullGCPtr<JS::Realm>, JS::NonnullGCPtr<DOM::Document>);
+    [[nodiscard]] static JS::NonnullGCPtr<Selection> create(JS::NonnullGCPtr<JS::Realm>, JS::NonnullGCPtr<DOM::Document>);
 
     virtual ~Selection() override;
 
diff --git a/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp b/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp
index 702de212be2..01f1ee83488 100644
--- a/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp
+++ b/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp
@@ -41,7 +41,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<ReadableStreamDefaultReader>> acquire_reada
     auto& realm = stream.realm();
 
     // 1. Let reader be a new ReadableStreamDefaultReader.
-    auto reader = TRY(realm.heap().allocate<ReadableStreamDefaultReader>(realm, realm));
+    auto reader = realm.heap().allocate<ReadableStreamDefaultReader>(realm, realm);
 
     // 2. Perform ? SetUpReadableStreamDefaultReader(reader, stream).
     TRY(set_up_readable_stream_default_reader(reader, stream));
@@ -56,7 +56,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<ReadableStreamBYOBReader>> acquire_readable
     auto& realm = stream.realm();
 
     // 1. Let reader be a new ReadableStreamBYOBReader.
-    auto reader = TRY(realm.heap().allocate<ReadableStreamBYOBReader>(realm, realm));
+    auto reader = realm.heap().allocate<ReadableStreamBYOBReader>(realm, realm);
 
     // 2. Perform ? SetUpReadableStreamBYOBReader(reader, stream).
     TRY(set_up_readable_stream_byob_reader(reader, stream));
@@ -834,7 +834,7 @@ WebIDL::ExceptionOr<void> set_up_readable_stream_default_controller_from_underly
     auto& realm = stream.realm();
 
     // 1. Let controller be a new ReadableStreamDefaultController.
-    auto controller = MUST_OR_THROW_OOM(stream.heap().allocate<ReadableStreamDefaultController>(realm, realm));
+    auto controller = stream.heap().allocate<ReadableStreamDefaultController>(realm, realm);
 
     // 2. Let startAlgorithm be an algorithm that returns undefined.
     StartAlgorithm start_algorithm = [] { return JS::js_undefined(); };
@@ -1172,13 +1172,13 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<ReadableStream>> create_readable_stream(JS:
     VERIFY(is_non_negative_number(JS::Value { *high_water_mark }));
 
     // 4. Let stream be a new ReadableStream.
-    auto stream = MUST_OR_THROW_OOM(realm.heap().allocate<ReadableStream>(realm, realm));
+    auto stream = realm.heap().allocate<ReadableStream>(realm, realm);
 
     // 5. Perform ! InitializeReadableStream(stream).
     initialize_readable_stream(*stream);
 
     // 6. Let controller be a new ReadableStreamDefaultController.
-    auto controller = MUST_OR_THROW_OOM(realm.heap().allocate<ReadableStreamDefaultController>(realm, realm));
+    auto controller = realm.heap().allocate<ReadableStreamDefaultController>(realm, realm);
 
     // 7. Perform ? SetUpReadableStreamDefaultController(stream, controller, startAlgorithm, pullAlgorithm, cancelAlgorithm, highWaterMark, sizeAlgorithm).
     TRY(set_up_readable_stream_default_controller(*stream, *controller, move(start_algorithm), move(pull_algorithm), move(cancel_algorithm), *high_water_mark, move(*size_algorithm)));
@@ -1194,13 +1194,13 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<WritableStream>> create_writable_stream(JS:
     VERIFY(is_non_negative_number(JS::Value { high_water_mark }));
 
     // 2. Let stream be a new WritableStream.
-    auto stream = MUST_OR_THROW_OOM(realm.heap().allocate<WritableStream>(realm, realm));
+    auto stream = realm.heap().allocate<WritableStream>(realm, realm);
 
     // 3. Perform ! InitializeWritableStream(stream).
     initialize_writable_stream(*stream);
 
     // 4. Let controller be a new WritableStreamDefaultController.
-    auto controller = MUST_OR_THROW_OOM(realm.heap().allocate<WritableStreamDefaultController>(realm, realm));
+    auto controller = realm.heap().allocate<WritableStreamDefaultController>(realm, realm);
 
     // 5. Perform ? SetUpWritableStreamDefaultController(stream, controller, startAlgorithm, writeAlgorithm, closeAlgorithm, abortAlgorithm, highWaterMark, sizeAlgorithm).
     TRY(set_up_writable_stream_default_controller(*stream, *controller, move(start_algorithm), move(write_algorithm), move(close_algorithm), move(abort_algorithm), high_water_mark, move(size_algorithm)));
@@ -1252,7 +1252,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<WritableStreamDefaultWriter>> acquire_writa
     auto& realm = stream.realm();
 
     // 1. Let writer be a new WritableStreamDefaultWriter.
-    auto writer = MUST_OR_THROW_OOM(stream.heap().allocate<WritableStreamDefaultWriter>(realm, realm));
+    auto writer = stream.heap().allocate<WritableStreamDefaultWriter>(realm, realm);
 
     // 2. Perform ? SetUpWritableStreamDefaultWriter(writer, stream).
     TRY(set_up_writable_stream_default_writer(*writer, stream));
@@ -1730,7 +1730,7 @@ WebIDL::ExceptionOr<void> set_up_readable_stream_controller_with_byte_reading_su
 
     // 4. Perform ! InitializeReadableStream(stream).
     // 5. Let controller be a new ReadableByteStreamController.
-    auto controller = MUST_OR_THROW_OOM(stream.heap().allocate<ReadableByteStreamController>(realm, realm));
+    auto controller = stream.heap().allocate<ReadableByteStreamController>(realm, realm);
 
     // 6. Perform ! SetUpReadableByteStreamController(stream, controller, startAlgorithm, pullAlgorithmWrapper, cancelAlgorithmWrapper, highWaterMark, undefined).
     TRY(set_up_readable_byte_stream_controller(stream, controller, move(start_algorithm), move(pull_algorithm_wrapper), move(cancel_algorithm_wrapper), high_water_mark, JS::js_undefined()));
@@ -2418,7 +2418,7 @@ WebIDL::ExceptionOr<void> set_up_writable_stream_default_controller(WritableStre
     reset_queue(controller);
 
     // 6. Set controller.[[signal]] to a new AbortSignal.
-    controller.set_signal(MUST_OR_THROW_OOM(realm.heap().allocate<DOM::AbortSignal>(realm, realm)));
+    controller.set_signal(realm.heap().allocate<DOM::AbortSignal>(realm, realm));
 
     // 7. Set controller.[[started]] to false.
     controller.set_started(false);
@@ -2489,7 +2489,7 @@ WebIDL::ExceptionOr<void> set_up_writable_stream_default_controller_from_underly
     auto& realm = stream.realm();
 
     // 1. Let controller be a new WritableStreamDefaultController.
-    auto controller = MUST_OR_THROW_OOM(realm.heap().allocate<WritableStreamDefaultController>(realm, realm));
+    auto controller = realm.heap().allocate<WritableStreamDefaultController>(realm, realm);
 
     // 2. Let startAlgorithm be an algorithm that returns undefined.
     StartAlgorithm start_algorithm = [] { return JS::js_undefined(); };
@@ -2916,7 +2916,7 @@ WebIDL::ExceptionOr<void> set_up_transform_stream_default_controller_from_transf
     auto& vm = realm.vm();
 
     // 1. Let controller be a new TransformStreamDefaultController.
-    auto controller = MUST_OR_THROW_OOM(realm.heap().allocate<TransformStreamDefaultController>(realm, realm));
+    auto controller = realm.heap().allocate<TransformStreamDefaultController>(realm, realm);
 
     // 2. Let transformAlgorithm be the following steps, taking a chunk argument:
     TransformAlgorithm transform_algorithm = [controller, &realm, &vm](JS::Value chunk) {
@@ -3308,7 +3308,7 @@ WebIDL::ExceptionOr<void> set_up_readable_byte_stream_controller_from_underlying
     auto& realm = stream.realm();
 
     // 1. Let controller be a new ReadableByteStreamController.
-    auto controller = MUST_OR_THROW_OOM(stream.heap().allocate<ReadableByteStreamController>(realm, realm));
+    auto controller = stream.heap().allocate<ReadableByteStreamController>(realm, realm);
 
     // 2. Let startAlgorithm be an algorithm that returns undefined.
     StartAlgorithm start_algorithm = [] { return JS::js_undefined(); };
diff --git a/Userland/Libraries/LibWeb/Streams/ByteLengthQueuingStrategy.cpp b/Userland/Libraries/LibWeb/Streams/ByteLengthQueuingStrategy.cpp
index 847afb101d5..afbfadf65dd 100644
--- a/Userland/Libraries/LibWeb/Streams/ByteLengthQueuingStrategy.cpp
+++ b/Userland/Libraries/LibWeb/Streams/ByteLengthQueuingStrategy.cpp
@@ -18,7 +18,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<ByteLengthQueuingStrategy>> ByteLengthQueui
 {
     // The new ByteLengthQueuingStrategy(init) constructor steps are:
     // 1. Set this.[[highWaterMark]] to init["highWaterMark"].
-    return MUST_OR_THROW_OOM(realm.heap().allocate<ByteLengthQueuingStrategy>(realm, realm, init.high_water_mark));
+    return realm.heap().allocate<ByteLengthQueuingStrategy>(realm, realm, init.high_water_mark);
 }
 
 ByteLengthQueuingStrategy::ByteLengthQueuingStrategy(JS::Realm& realm, double high_water_mark)
diff --git a/Userland/Libraries/LibWeb/Streams/CountQueuingStrategy.cpp b/Userland/Libraries/LibWeb/Streams/CountQueuingStrategy.cpp
index 1745bb216c6..8e0ccc40809 100644
--- a/Userland/Libraries/LibWeb/Streams/CountQueuingStrategy.cpp
+++ b/Userland/Libraries/LibWeb/Streams/CountQueuingStrategy.cpp
@@ -18,7 +18,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<CountQueuingStrategy>> CountQueuingStrategy
 {
     // The new CountQueuingStrategy(init) constructor steps are:
     // 1. Set this.[[highWaterMark]] to init["highWaterMark"].
-    return MUST_OR_THROW_OOM(realm.heap().allocate<CountQueuingStrategy>(realm, realm, init.high_water_mark));
+    return realm.heap().allocate<CountQueuingStrategy>(realm, realm, init.high_water_mark);
 }
 
 CountQueuingStrategy::CountQueuingStrategy(JS::Realm& realm, double high_water_mark)
diff --git a/Userland/Libraries/LibWeb/Streams/ReadableStream.cpp b/Userland/Libraries/LibWeb/Streams/ReadableStream.cpp
index b8e799ff806..b695c27faad 100644
--- a/Userland/Libraries/LibWeb/Streams/ReadableStream.cpp
+++ b/Userland/Libraries/LibWeb/Streams/ReadableStream.cpp
@@ -23,7 +23,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<ReadableStream>> ReadableStream::construct_
 {
     auto& vm = realm.vm();
 
-    auto readable_stream = MUST_OR_THROW_OOM(realm.heap().allocate<ReadableStream>(realm, realm));
+    auto readable_stream = realm.heap().allocate<ReadableStream>(realm, realm);
 
     // 1. If underlyingSource is missing, set it to null.
     auto underlying_source = underlying_source_object.has_value() ? JS::Value(underlying_source_object.value().ptr()) : JS::js_null();
diff --git a/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.cpp b/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.cpp
index dc03e9bb9f1..6e6bb49e60a 100644
--- a/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.cpp
+++ b/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.cpp
@@ -33,7 +33,7 @@ void ReadLoopReadRequest::visit_edges(Visitor& visitor)
 // https://streams.spec.whatwg.org/#default-reader-constructor
 WebIDL::ExceptionOr<JS::NonnullGCPtr<ReadableStreamDefaultReader>> ReadableStreamDefaultReader::construct_impl(JS::Realm& realm, JS::NonnullGCPtr<ReadableStream> stream)
 {
-    auto reader = TRY(realm.heap().allocate<ReadableStreamDefaultReader>(realm, realm));
+    auto reader = realm.heap().allocate<ReadableStreamDefaultReader>(realm, realm);
 
     // 1. Perform ? SetUpReadableStreamDefaultReader(this, stream);
     TRY(set_up_readable_stream_default_reader(reader, *stream));
diff --git a/Userland/Libraries/LibWeb/Streams/TransformStream.cpp b/Userland/Libraries/LibWeb/Streams/TransformStream.cpp
index ff54019c50e..c3319b99ee0 100644
--- a/Userland/Libraries/LibWeb/Streams/TransformStream.cpp
+++ b/Userland/Libraries/LibWeb/Streams/TransformStream.cpp
@@ -20,7 +20,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<TransformStream>> TransformStream::construc
 {
     auto& vm = realm.vm();
 
-    auto stream = MUST_OR_THROW_OOM(realm.heap().allocate<TransformStream>(realm, realm));
+    auto stream = realm.heap().allocate<TransformStream>(realm, realm);
 
     // 1. If transformer is missing, set it to null.
     auto transformer = transformer_object.has_value() ? JS::Value { transformer_object.value().ptr() } : JS::js_null();
diff --git a/Userland/Libraries/LibWeb/Streams/WritableStream.cpp b/Userland/Libraries/LibWeb/Streams/WritableStream.cpp
index 3428eb63d52..9b1c6ecd530 100644
--- a/Userland/Libraries/LibWeb/Streams/WritableStream.cpp
+++ b/Userland/Libraries/LibWeb/Streams/WritableStream.cpp
@@ -21,7 +21,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<WritableStream>> WritableStream::construct_
 {
     auto& vm = realm.vm();
 
-    auto writable_stream = MUST_OR_THROW_OOM(realm.heap().allocate<WritableStream>(realm, realm));
+    auto writable_stream = realm.heap().allocate<WritableStream>(realm, realm);
 
     // 1. If underlyingSink is missing, set it to null.
     auto underlying_sink = underlying_sink_object.has_value() ? JS::Value(underlying_sink_object.value().ptr()) : JS::js_null();
diff --git a/Userland/Libraries/LibWeb/Streams/WritableStreamDefaultWriter.cpp b/Userland/Libraries/LibWeb/Streams/WritableStreamDefaultWriter.cpp
index 9996e2e998d..2ca9c382367 100644
--- a/Userland/Libraries/LibWeb/Streams/WritableStreamDefaultWriter.cpp
+++ b/Userland/Libraries/LibWeb/Streams/WritableStreamDefaultWriter.cpp
@@ -16,7 +16,7 @@ namespace Web::Streams {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<WritableStreamDefaultWriter>> WritableStreamDefaultWriter::construct_impl(JS::Realm& realm, JS::NonnullGCPtr<WritableStream> stream)
 {
-    auto writer = MUST_OR_THROW_OOM(realm.heap().allocate<WritableStreamDefaultWriter>(realm, realm));
+    auto writer = realm.heap().allocate<WritableStreamDefaultWriter>(realm, realm);
 
     // 1. Perform ? SetUpWritableStreamDefaultWriter(this, stream).
     TRY(set_up_writable_stream_default_writer(*writer, stream));
diff --git a/Userland/Libraries/LibWeb/UIEvents/FocusEvent.cpp b/Userland/Libraries/LibWeb/UIEvents/FocusEvent.cpp
index 868d399b7cd..a666b996334 100644
--- a/Userland/Libraries/LibWeb/UIEvents/FocusEvent.cpp
+++ b/Userland/Libraries/LibWeb/UIEvents/FocusEvent.cpp
@@ -11,7 +11,7 @@ namespace Web::UIEvents {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<FocusEvent>> FocusEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, FocusEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<FocusEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<FocusEvent>(realm, realm, event_name, event_init);
 }
 
 FocusEvent::FocusEvent(JS::Realm& realm, FlyString const& event_name, FocusEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/UIEvents/KeyboardEvent.cpp b/Userland/Libraries/LibWeb/UIEvents/KeyboardEvent.cpp
index 5fa279c9b9b..5e4bbc24c3e 100644
--- a/Userland/Libraries/LibWeb/UIEvents/KeyboardEvent.cpp
+++ b/Userland/Libraries/LibWeb/UIEvents/KeyboardEvent.cpp
@@ -503,12 +503,10 @@ static DOMKeyLocation get_event_location(KeyCode platform_key, unsigned modifier
     return DOMKeyLocation::Standard;
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<KeyboardEvent>> KeyboardEvent::create_from_platform_event(JS::Realm& realm, FlyString const& event_name, KeyCode platform_key, unsigned modifiers, u32 code_point)
+JS::NonnullGCPtr<KeyboardEvent> KeyboardEvent::create_from_platform_event(JS::Realm& realm, FlyString const& event_name, KeyCode platform_key, unsigned modifiers, u32 code_point)
 {
-    auto& vm = realm.vm();
-
-    auto event_key = TRY_OR_THROW_OOM(vm, get_event_key(platform_key, code_point));
-    auto event_code = TRY_OR_THROW_OOM(vm, get_event_code(platform_key, modifiers));
+    auto event_key = MUST(get_event_key(platform_key, code_point));
+    auto event_code = MUST(get_event_code(platform_key, modifiers));
 
     auto key_code = determine_key_code(platform_key, code_point);
     KeyboardEventInit event_init {};
@@ -542,9 +540,9 @@ bool KeyboardEvent::get_modifier_state(String const& key_arg)
     return false;
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<KeyboardEvent>> KeyboardEvent::create(JS::Realm& realm, FlyString const& event_name, KeyboardEventInit const& event_init)
+JS::NonnullGCPtr<KeyboardEvent> KeyboardEvent::create(JS::Realm& realm, FlyString const& event_name, KeyboardEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<KeyboardEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<KeyboardEvent>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<KeyboardEvent>> KeyboardEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, KeyboardEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/UIEvents/KeyboardEvent.h b/Userland/Libraries/LibWeb/UIEvents/KeyboardEvent.h
index 9f2ef054f8d..f7aa304e514 100644
--- a/Userland/Libraries/LibWeb/UIEvents/KeyboardEvent.h
+++ b/Userland/Libraries/LibWeb/UIEvents/KeyboardEvent.h
@@ -36,9 +36,9 @@ class KeyboardEvent final : public UIEvent {
     WEB_PLATFORM_OBJECT(KeyboardEvent, UIEvent);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<KeyboardEvent>> create(JS::Realm&, FlyString const& event_name, KeyboardEventInit const& event_init = {});
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<KeyboardEvent>> construct_impl(JS::Realm&, FlyString const& event_name, KeyboardEventInit const& event_init);
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<KeyboardEvent>> create_from_platform_event(JS::Realm&, FlyString const& event_name, KeyCode, unsigned modifiers, u32 code_point);
+    [[nodiscard]] static JS::NonnullGCPtr<KeyboardEvent> create(JS::Realm&, FlyString const& event_name, KeyboardEventInit const& = {});
+    [[nodiscard]] static JS::NonnullGCPtr<KeyboardEvent> create_from_platform_event(JS::Realm&, FlyString const& event_name, KeyCode, unsigned modifiers, u32 code_point);
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<KeyboardEvent>> construct_impl(JS::Realm&, FlyString const& event_name, KeyboardEventInit const&);
 
     virtual ~KeyboardEvent() override;
 
diff --git a/Userland/Libraries/LibWeb/UIEvents/MouseEvent.cpp b/Userland/Libraries/LibWeb/UIEvents/MouseEvent.cpp
index 39f69d07d36..217a1fd7d91 100644
--- a/Userland/Libraries/LibWeb/UIEvents/MouseEvent.cpp
+++ b/Userland/Libraries/LibWeb/UIEvents/MouseEvent.cpp
@@ -54,9 +54,9 @@ static i16 determine_button(unsigned mouse_button)
     }
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<MouseEvent>> MouseEvent::create(JS::Realm& realm, FlyString const& event_name, MouseEventInit const& event_init)
+JS::NonnullGCPtr<MouseEvent> MouseEvent::create(JS::Realm& realm, FlyString const& event_name, MouseEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<MouseEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<MouseEvent>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<MouseEvent>> MouseEvent::create_from_platform_event(JS::Realm& realm, FlyString const& event_name, CSSPixelPoint offset, CSSPixelPoint client_offset, CSSPixelPoint page_offset, unsigned buttons, unsigned mouse_button)
diff --git a/Userland/Libraries/LibWeb/UIEvents/MouseEvent.h b/Userland/Libraries/LibWeb/UIEvents/MouseEvent.h
index 394bf317367..f06e1f98fab 100644
--- a/Userland/Libraries/LibWeb/UIEvents/MouseEvent.h
+++ b/Userland/Libraries/LibWeb/UIEvents/MouseEvent.h
@@ -29,7 +29,7 @@ class MouseEvent : public UIEvent {
     WEB_PLATFORM_OBJECT(MouseEvent, UIEvent);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<MouseEvent>> create(JS::Realm&, FlyString const& event_name, MouseEventInit const& event_init = {});
+    [[nodiscard]] static JS::NonnullGCPtr<MouseEvent> create(JS::Realm&, FlyString const& event_name, MouseEventInit const& = {});
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<MouseEvent>> create_from_platform_event(JS::Realm&, FlyString const& event_name, CSSPixelPoint offset, CSSPixelPoint client_offset, CSSPixelPoint page_offset, unsigned buttons, unsigned mouse_button = 1);
 
     virtual ~MouseEvent() override;
diff --git a/Userland/Libraries/LibWeb/UIEvents/UIEvent.cpp b/Userland/Libraries/LibWeb/UIEvents/UIEvent.cpp
index 2c3c6e8e308..80af8ff2e13 100644
--- a/Userland/Libraries/LibWeb/UIEvents/UIEvent.cpp
+++ b/Userland/Libraries/LibWeb/UIEvents/UIEvent.cpp
@@ -9,14 +9,14 @@
 
 namespace Web::UIEvents {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<UIEvent>> UIEvent::create(JS::Realm& realm, FlyString const& event_name)
+JS::NonnullGCPtr<UIEvent> UIEvent::create(JS::Realm& realm, FlyString const& event_name)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<UIEvent>(realm, realm, event_name));
+    return realm.heap().allocate<UIEvent>(realm, realm, event_name);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<UIEvent>> UIEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, UIEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<UIEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<UIEvent>(realm, realm, event_name, event_init);
 }
 
 UIEvent::UIEvent(JS::Realm& realm, FlyString const& event_name)
diff --git a/Userland/Libraries/LibWeb/UIEvents/UIEvent.h b/Userland/Libraries/LibWeb/UIEvents/UIEvent.h
index 02346315fc9..3879c1b0e41 100644
--- a/Userland/Libraries/LibWeb/UIEvents/UIEvent.h
+++ b/Userland/Libraries/LibWeb/UIEvents/UIEvent.h
@@ -21,7 +21,7 @@ class UIEvent : public DOM::Event {
     WEB_PLATFORM_OBJECT(UIEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<UIEvent>> create(JS::Realm&, FlyString const& type);
+    [[nodiscard]] static JS::NonnullGCPtr<UIEvent> create(JS::Realm&, FlyString const& type);
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<UIEvent>> construct_impl(JS::Realm&, FlyString const& event_name, UIEventInit const& event_init);
 
     virtual ~UIEvent() override;
diff --git a/Userland/Libraries/LibWeb/UIEvents/WheelEvent.cpp b/Userland/Libraries/LibWeb/UIEvents/WheelEvent.cpp
index 31a11b89585..85093dcbda3 100644
--- a/Userland/Libraries/LibWeb/UIEvents/WheelEvent.cpp
+++ b/Userland/Libraries/LibWeb/UIEvents/WheelEvent.cpp
@@ -29,9 +29,9 @@ void WheelEvent::initialize(JS::Realm& realm)
     set_prototype(&Bindings::ensure_web_prototype<Bindings::WheelEventPrototype>(realm, "WheelEvent"));
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<WheelEvent>> WheelEvent::create(JS::Realm& realm, FlyString const& event_name, WheelEventInit const& event_init)
+JS::NonnullGCPtr<WheelEvent> WheelEvent::create(JS::Realm& realm, FlyString const& event_name, WheelEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<WheelEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<WheelEvent>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<WheelEvent>> WheelEvent::create_from_platform_event(JS::Realm& realm, FlyString const& event_name, CSSPixels offset_x, CSSPixels offset_y, CSSPixels client_x, CSSPixels client_y, double delta_x, double delta_y, unsigned buttons, unsigned button)
diff --git a/Userland/Libraries/LibWeb/UIEvents/WheelEvent.h b/Userland/Libraries/LibWeb/UIEvents/WheelEvent.h
index 93a1460c6ff..1a735e2133a 100644
--- a/Userland/Libraries/LibWeb/UIEvents/WheelEvent.h
+++ b/Userland/Libraries/LibWeb/UIEvents/WheelEvent.h
@@ -29,7 +29,7 @@ class WheelEvent final : public MouseEvent {
     WEB_PLATFORM_OBJECT(WheelEvent, MouseEvent);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<WheelEvent>> create(JS::Realm&, FlyString const& event_name, WheelEventInit const& event_init = {});
+    [[nodiscard]] static JS::NonnullGCPtr<WheelEvent> create(JS::Realm&, FlyString const& event_name, WheelEventInit const& event_init = {});
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<WheelEvent>> create_from_platform_event(JS::Realm&, FlyString const& event_name, CSSPixels offset_x, CSSPixels offset_y, CSSPixels client_x, CSSPixels client_y, double delta_x, double delta_y, unsigned buttons, unsigned button);
 
     virtual ~WheelEvent() override;
diff --git a/Userland/Libraries/LibWeb/URL/URL.cpp b/Userland/Libraries/LibWeb/URL/URL.cpp
index a1a6a943115..05f1af05c7f 100644
--- a/Userland/Libraries/LibWeb/URL/URL.cpp
+++ b/Userland/Libraries/LibWeb/URL/URL.cpp
@@ -16,9 +16,9 @@
 
 namespace Web::URL {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<URL>> URL::create(JS::Realm& realm, AK::URL url, JS::NonnullGCPtr<URLSearchParams> query)
+JS::NonnullGCPtr<URL> URL::create(JS::Realm& realm, AK::URL url, JS::NonnullGCPtr<URLSearchParams> query)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<URL>(realm, realm, move(url), move(query)));
+    return realm.heap().allocate<URL>(realm, realm, move(url), move(query));
 }
 
 // https://url.spec.whatwg.org/#api-url-parser
@@ -67,7 +67,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<URL>> URL::construct_impl(JS::Realm& realm,
     auto query_object = MUST(URLSearchParams::construct_impl(realm, query));
 
     // 6. Initialize this’s query object with query.
-    auto result_url = TRY(URL::create(realm, parsed_url.release_value(), move(query_object)));
+    auto result_url = URL::create(realm, parsed_url.release_value(), move(query_object));
 
     // 7. Set this’s query object’s URL object to this.
     result_url->m_query->m_url = result_url;
diff --git a/Userland/Libraries/LibWeb/URL/URL.h b/Userland/Libraries/LibWeb/URL/URL.h
index 2da8b0fcbce..b236a85ad17 100644
--- a/Userland/Libraries/LibWeb/URL/URL.h
+++ b/Userland/Libraries/LibWeb/URL/URL.h
@@ -19,7 +19,7 @@ class URL : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(URL, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<URL>> create(JS::Realm&, AK::URL url, JS::NonnullGCPtr<URLSearchParams> query);
+    [[nodiscard]] static JS::NonnullGCPtr<URL> create(JS::Realm&, AK::URL, JS::NonnullGCPtr<URLSearchParams> query);
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<URL>> construct_impl(JS::Realm&, String const& url, Optional<String> const& base = {});
 
     virtual ~URL() override;
diff --git a/Userland/Libraries/LibWeb/URL/URLSearchParams.cpp b/Userland/Libraries/LibWeb/URL/URLSearchParams.cpp
index 10767229c90..9c4401c4edc 100644
--- a/Userland/Libraries/LibWeb/URL/URLSearchParams.cpp
+++ b/Userland/Libraries/LibWeb/URL/URLSearchParams.cpp
@@ -118,7 +118,7 @@ ErrorOr<Vector<QueryParam>> url_decode(StringView input)
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<URLSearchParams>> URLSearchParams::create(JS::Realm& realm, Vector<QueryParam> list)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<URLSearchParams>(realm, realm, move(list)));
+    return realm.heap().allocate<URLSearchParams>(realm, realm, move(list));
 }
 
 // https://url.spec.whatwg.org/#dom-urlsearchparams-urlsearchparams
diff --git a/Userland/Libraries/LibWeb/URL/URLSearchParamsIterator.cpp b/Userland/Libraries/LibWeb/URL/URLSearchParamsIterator.cpp
index b4937eee446..ba058645c28 100644
--- a/Userland/Libraries/LibWeb/URL/URLSearchParamsIterator.cpp
+++ b/Userland/Libraries/LibWeb/URL/URLSearchParamsIterator.cpp
@@ -15,7 +15,7 @@ namespace Web::Bindings {
 template<>
 void Intrinsics::create_web_prototype_and_constructor<URLSearchParamsIteratorPrototype>(JS::Realm& realm)
 {
-    auto prototype = heap().allocate<URLSearchParamsIteratorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    auto prototype = heap().allocate<URLSearchParamsIteratorPrototype>(realm, realm);
     m_prototypes.set("URLSearchParamsIterator"sv, prototype);
 }
 
@@ -25,7 +25,7 @@ namespace Web::URL {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<URLSearchParamsIterator>> URLSearchParamsIterator::create(URLSearchParams const& url_search_params, JS::Object::PropertyKind iteration_kind)
 {
-    return MUST_OR_THROW_OOM(url_search_params.heap().allocate<URLSearchParamsIterator>(url_search_params.realm(), url_search_params, iteration_kind));
+    return url_search_params.heap().allocate<URLSearchParamsIterator>(url_search_params.realm(), url_search_params, iteration_kind);
 }
 
 URLSearchParamsIterator::URLSearchParamsIterator(URLSearchParams const& url_search_params, JS::Object::PropertyKind iteration_kind)
diff --git a/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.cpp b/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.cpp
index d3ed05d9aaf..b2c5c3727ff 100644
--- a/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.cpp
+++ b/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.cpp
@@ -88,7 +88,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<PerformanceMark>> PerformanceMark::construc
     }
 
     // 2. Create a new PerformanceMark object (entry) with the current global object's realm.
-    return MUST_OR_THROW_OOM(realm.heap().allocate<PerformanceMark>(realm, realm, name, start_time, duration, detail));
+    return realm.heap().allocate<PerformanceMark>(realm, realm, name, start_time, duration, detail);
 }
 
 FlyString const& PerformanceMark::entry_type() const
diff --git a/Userland/Libraries/LibWeb/UserTiming/PerformanceMeasure.cpp b/Userland/Libraries/LibWeb/UserTiming/PerformanceMeasure.cpp
index ee6f8117b3a..0c88c27a24d 100644
--- a/Userland/Libraries/LibWeb/UserTiming/PerformanceMeasure.cpp
+++ b/Userland/Libraries/LibWeb/UserTiming/PerformanceMeasure.cpp
@@ -24,9 +24,9 @@ PerformanceMeasure::PerformanceMeasure(JS::Realm& realm, String const& name, Hig
 
 PerformanceMeasure::~PerformanceMeasure() = default;
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<PerformanceMeasure>> PerformanceMeasure::create(JS::Realm& realm, String const& measure_name, HighResolutionTime::DOMHighResTimeStamp start_time, HighResolutionTime::DOMHighResTimeStamp duration, JS::Value detail)
+JS::NonnullGCPtr<PerformanceMeasure> PerformanceMeasure::create(JS::Realm& realm, String const& measure_name, HighResolutionTime::DOMHighResTimeStamp start_time, HighResolutionTime::DOMHighResTimeStamp duration, JS::Value detail)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<PerformanceMeasure>(realm, realm, measure_name, start_time, duration, detail));
+    return realm.heap().allocate<PerformanceMeasure>(realm, realm, measure_name, start_time, duration, detail);
 }
 
 FlyString const& PerformanceMeasure::entry_type() const
diff --git a/Userland/Libraries/LibWeb/UserTiming/PerformanceMeasure.h b/Userland/Libraries/LibWeb/UserTiming/PerformanceMeasure.h
index 7cd9aba2046..9c324693ef7 100644
--- a/Userland/Libraries/LibWeb/UserTiming/PerformanceMeasure.h
+++ b/Userland/Libraries/LibWeb/UserTiming/PerformanceMeasure.h
@@ -25,7 +25,7 @@ class PerformanceMeasure final : public PerformanceTimeline::PerformanceEntry {
 public:
     virtual ~PerformanceMeasure();
 
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<PerformanceMeasure>> create(JS::Realm&, String const& measure_name, HighResolutionTime::DOMHighResTimeStamp start_time, HighResolutionTime::DOMHighResTimeStamp duration, JS::Value detail);
+    [[nodiscard]] static JS::NonnullGCPtr<PerformanceMeasure> create(JS::Realm&, String const& measure_name, HighResolutionTime::DOMHighResTimeStamp start_time, HighResolutionTime::DOMHighResTimeStamp duration, JS::Value detail);
 
     // NOTE: These three functions are answered by the registry for the given entry type.
     // https://w3c.github.io/timing-entrytypes-registry/#registry
diff --git a/Userland/Libraries/LibWeb/WebAssembly/Instance.cpp b/Userland/Libraries/LibWeb/WebAssembly/Instance.cpp
index 3ae7aef44b7..9fb77abf59f 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/Instance.cpp
+++ b/Userland/Libraries/LibWeb/WebAssembly/Instance.cpp
@@ -28,7 +28,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Instance>> Instance::construct_impl(JS::Rea
     auto& vm = realm.vm();
 
     auto index = TRY(Detail::instantiate_module(vm, module.module()));
-    return MUST_OR_THROW_OOM(vm.heap().allocate<Instance>(realm, realm, index));
+    return vm.heap().allocate<Instance>(realm, realm, index);
 }
 
 Instance::Instance(JS::Realm& realm, size_t index)
@@ -62,7 +62,7 @@ void Instance::initialize(JS::Realm& realm)
             [&](Wasm::MemoryAddress const& address) {
                 Optional<JS::GCPtr<Memory>> object = cache.memory_instances.get(address);
                 if (!object.has_value()) {
-                    object = MUST(heap().allocate<Memory>(realm, realm, address));
+                    object = heap().allocate<Memory>(realm, realm, address);
                     cache.memory_instances.set(address, *object);
                 }
 
@@ -71,7 +71,7 @@ void Instance::initialize(JS::Realm& realm)
             [&](Wasm::TableAddress const& address) {
                 Optional<JS::GCPtr<Table>> object = cache.table_instances.get(address);
                 if (!object.has_value()) {
-                    object = MUST(heap().allocate<Table>(realm, realm, address));
+                    object = heap().allocate<Table>(realm, realm, address);
                     cache.table_instances.set(address, *object);
                 }
 
diff --git a/Userland/Libraries/LibWeb/WebAssembly/Memory.cpp b/Userland/Libraries/LibWeb/WebAssembly/Memory.cpp
index aef12f1b165..864baf1c446 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/Memory.cpp
+++ b/Userland/Libraries/LibWeb/WebAssembly/Memory.cpp
@@ -25,7 +25,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Memory>> Memory::construct_impl(JS::Realm&
     if (!address.has_value())
         return vm.throw_completion<JS::TypeError>("Wasm Memory allocation failed"sv);
 
-    auto memory_object = MUST_OR_THROW_OOM(vm.heap().allocate<Memory>(realm, realm, *address));
+    auto memory_object = vm.heap().allocate<Memory>(realm, realm, *address);
     Detail::s_abstract_machine.store().get(*address)->successful_grow_hook = [memory_object] {
         MUST(memory_object->reset_the_memory_buffer());
     };
diff --git a/Userland/Libraries/LibWeb/WebAssembly/Module.cpp b/Userland/Libraries/LibWeb/WebAssembly/Module.cpp
index b92db841c5b..c4d45dbcbe4 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/Module.cpp
+++ b/Userland/Libraries/LibWeb/WebAssembly/Module.cpp
@@ -19,7 +19,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Module>> Module::construct_impl(JS::Realm&
     auto& vm = realm.vm();
 
     auto index = TRY(Detail::parse_module(vm, bytes.cell()));
-    return MUST_OR_THROW_OOM(vm.heap().allocate<Module>(realm, realm, index));
+    return vm.heap().allocate<Module>(realm, realm, index);
 }
 
 Module::Module(JS::Realm& realm, size_t index)
diff --git a/Userland/Libraries/LibWeb/WebAssembly/Table.cpp b/Userland/Libraries/LibWeb/WebAssembly/Table.cpp
index a2e4354aee3..0c192fe1c6b 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/Table.cpp
+++ b/Userland/Libraries/LibWeb/WebAssembly/Table.cpp
@@ -52,7 +52,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Table>> Table::construct_impl(JS::Realm& re
     for (auto& element : table.elements())
         element = reference;
 
-    return MUST_OR_THROW_OOM(vm.heap().allocate<Table>(realm, realm, *address));
+    return vm.heap().allocate<Table>(realm, realm, *address);
 }
 
 Table::Table(JS::Realm& realm, Wasm::TableAddress address)
diff --git a/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.cpp b/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.cpp
index ede245a4a64..d6092354ae5 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.cpp
+++ b/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.cpp
@@ -88,7 +88,7 @@ WebIDL::ExceptionOr<JS::Value> compile(JS::VM& vm, JS::Handle<JS::Object>& bytes
     if (module.is_error()) {
         promise->reject(*module.release_error().value());
     } else {
-        auto module_object = MUST_OR_THROW_OOM(vm.heap().allocate<Module>(realm, realm, module.release_value()));
+        auto module_object = vm.heap().allocate<Module>(realm, realm, module.release_value());
         promise->fulfill(module_object);
     }
 
@@ -118,8 +118,8 @@ WebIDL::ExceptionOr<JS::Value> instantiate(JS::VM& vm, JS::Handle<JS::Object>& b
     if (result.is_error()) {
         promise->reject(*result.release_error().value());
     } else {
-        auto module_object = MUST_OR_THROW_OOM(vm.heap().allocate<Module>(realm, realm, Detail::s_compiled_modules.size() - 1));
-        auto instance_object = MUST_OR_THROW_OOM(vm.heap().allocate<Instance>(realm, realm, result.release_value()));
+        auto module_object = vm.heap().allocate<Module>(realm, realm, Detail::s_compiled_modules.size() - 1);
+        auto instance_object = vm.heap().allocate<Instance>(realm, realm, result.release_value());
 
         auto object = JS::Object::create(realm, nullptr);
         object->define_direct_property("module", module_object, JS::default_attributes);
@@ -145,7 +145,7 @@ WebIDL::ExceptionOr<JS::Value> instantiate(JS::VM& vm, Module const& module_obje
     if (result.is_error()) {
         promise->reject(*result.release_error().value());
     } else {
-        auto instance_object = MUST_OR_THROW_OOM(vm.heap().allocate<Instance>(realm, realm, result.release_value()));
+        auto instance_object = vm.heap().allocate<Instance>(realm, realm, result.release_value());
         promise->fulfill(instance_object);
     }
 
@@ -426,7 +426,7 @@ JS::Value to_js_value(JS::VM& vm, Wasm::Value& wasm_value)
     auto& realm = *vm.current_realm();
     switch (wasm_value.type().kind()) {
     case Wasm::ValueType::I64:
-        return realm.heap().allocate<JS::BigInt>(realm, ::Crypto::SignedBigInteger { wasm_value.to<i64>().value() }).release_allocated_value_but_fixme_should_propagate_errors();
+        return realm.heap().allocate<JS::BigInt>(realm, ::Crypto::SignedBigInteger { wasm_value.to<i64>().value() });
     case Wasm::ValueType::I32:
         return JS::Value(wasm_value.to<i32>().value());
     case Wasm::ValueType::F64:
diff --git a/Userland/Libraries/LibWeb/WebAudio/AudioContext.cpp b/Userland/Libraries/LibWeb/WebAudio/AudioContext.cpp
index 35882baa0ed..058349e3595 100644
--- a/Userland/Libraries/LibWeb/WebAudio/AudioContext.cpp
+++ b/Userland/Libraries/LibWeb/WebAudio/AudioContext.cpp
@@ -15,7 +15,7 @@ namespace Web::WebAudio {
 // https://webaudio.github.io/web-audio-api/#dom-audiocontext-audiocontext
 WebIDL::ExceptionOr<JS::NonnullGCPtr<AudioContext>> AudioContext::construct_impl(JS::Realm& realm, AudioContextOptions const& context_options)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<AudioContext>(realm, realm, context_options));
+    return realm.heap().allocate<AudioContext>(realm, realm, context_options);
 }
 
 AudioContext::AudioContext(JS::Realm& realm, AudioContextOptions const& context_options)
@@ -72,7 +72,7 @@ AudioContext::AudioContext(JS::Realm& realm, AudioContextOptions const& context_
             BaseAudioContext::set_control_state(Bindings::AudioContextState::Running);
 
             // 5.3.2: queue a media element task to fire an event named statechange at the AudioContext.
-            this->dispatch_event(DOM::Event::create(realm, HTML::EventNames::statechange).release_value_but_fixme_should_propagate_errors());
+            this->dispatch_event(DOM::Event::create(realm, HTML::EventNames::statechange));
         });
     }
 }
@@ -174,7 +174,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<JS::Promise>> AudioContext::resume()
 
             // 7.5.4.2: queue a media element task to fire an event named statechange at the AudioContext.
             queue_a_media_element_task([&realm, this]() {
-                this->dispatch_event(DOM::Event::create(realm, HTML::EventNames::statechange).release_value_but_fixme_should_propagate_errors());
+                this->dispatch_event(DOM::Event::create(realm, HTML::EventNames::statechange));
             });
         }
     });
@@ -229,7 +229,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<JS::Promise>> AudioContext::suspend()
 
             // 7.3.2.2: queue a media element task to fire an event named statechange at the AudioContext.
             queue_a_media_element_task([&realm, this]() {
-                this->dispatch_event(DOM::Event::create(realm, HTML::EventNames::statechange).release_value_but_fixme_should_propagate_errors());
+                this->dispatch_event(DOM::Event::create(realm, HTML::EventNames::statechange));
             });
         }
     });
@@ -280,7 +280,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<JS::Promise>> AudioContext::close()
 
         // 5.4.2.2: queue a media element task to fire an event named statechange at the AudioContext.
         // FIXME: Attempting to queue another task in here causes an assertion fail at Vector.h:148
-        this->dispatch_event(DOM::Event::create(realm, HTML::EventNames::statechange).release_value_but_fixme_should_propagate_errors());
+        this->dispatch_event(DOM::Event::create(realm, HTML::EventNames::statechange));
     });
 
     // 6. Return promise
diff --git a/Userland/Libraries/LibWeb/WebGL/WebGLContextEvent.cpp b/Userland/Libraries/LibWeb/WebGL/WebGLContextEvent.cpp
index c9a57491e3d..2049bc33832 100644
--- a/Userland/Libraries/LibWeb/WebGL/WebGLContextEvent.cpp
+++ b/Userland/Libraries/LibWeb/WebGL/WebGLContextEvent.cpp
@@ -9,9 +9,9 @@
 
 namespace Web::WebGL {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<WebGLContextEvent>> WebGLContextEvent::create(JS::Realm& realm, FlyString const& event_name, WebGLContextEventInit const& event_init)
+JS::NonnullGCPtr<WebGLContextEvent> WebGLContextEvent::create(JS::Realm& realm, FlyString const& event_name, WebGLContextEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<WebGLContextEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<WebGLContextEvent>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<WebGLContextEvent>> WebGLContextEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, WebGLContextEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/WebGL/WebGLContextEvent.h b/Userland/Libraries/LibWeb/WebGL/WebGLContextEvent.h
index bf2cb811ebd..a4dad188e30 100644
--- a/Userland/Libraries/LibWeb/WebGL/WebGLContextEvent.h
+++ b/Userland/Libraries/LibWeb/WebGL/WebGLContextEvent.h
@@ -20,8 +20,8 @@ class WebGLContextEvent final : public DOM::Event {
     WEB_PLATFORM_OBJECT(WebGLContextEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<WebGLContextEvent>> create(JS::Realm&, FlyString const& type, WebGLContextEventInit const& event_init);
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<WebGLContextEvent>> construct_impl(JS::Realm&, FlyString const& type, WebGLContextEventInit const& event_init);
+    [[nodiscard]] static JS::NonnullGCPtr<WebGLContextEvent> create(JS::Realm&, FlyString const& type, WebGLContextEventInit const&);
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<WebGLContextEvent>> construct_impl(JS::Realm&, FlyString const& type, WebGLContextEventInit const&);
 
     virtual ~WebGLContextEvent() override;
 
diff --git a/Userland/Libraries/LibWeb/WebGL/WebGLRenderingContext.cpp b/Userland/Libraries/LibWeb/WebGL/WebGLRenderingContext.cpp
index 6f5ecf3b1c2..76e5a2a767c 100644
--- a/Userland/Libraries/LibWeb/WebGL/WebGLRenderingContext.cpp
+++ b/Userland/Libraries/LibWeb/WebGL/WebGLRenderingContext.cpp
@@ -18,7 +18,7 @@ static void fire_webgl_context_event(HTML::HTMLCanvasElement& canvas_element, Fl
 {
     // To fire a WebGL context event named e means that an event using the WebGLContextEvent interface, with its type attribute [DOM4] initialized to e, its cancelable attribute initialized to true, and its isTrusted attribute [DOM4] initialized to true, is to be dispatched at the given object.
     // FIXME: Consider setting a status message.
-    auto event = WebGLContextEvent::create(canvas_element.realm(), type, WebGLContextEventInit {}).release_value_but_fixme_should_propagate_errors();
+    auto event = WebGLContextEvent::create(canvas_element.realm(), type, WebGLContextEventInit {});
     event->set_is_trusted(true);
     event->set_cancelable(true);
     canvas_element.dispatch_event(*event);
@@ -47,7 +47,7 @@ JS::ThrowCompletionOr<JS::GCPtr<WebGLRenderingContext>> WebGLRenderingContext::c
         fire_webgl_context_creation_error(canvas_element);
         return JS::GCPtr<WebGLRenderingContext> { nullptr };
     }
-    return MUST_OR_THROW_OOM(realm.heap().allocate<WebGLRenderingContext>(realm, realm, canvas_element, context_or_error.release_value(), context_attributes, context_attributes));
+    return realm.heap().allocate<WebGLRenderingContext>(realm, realm, canvas_element, context_or_error.release_value(), context_attributes, context_attributes);
 }
 
 WebGLRenderingContext::WebGLRenderingContext(JS::Realm& realm, HTML::HTMLCanvasElement& canvas_element, NonnullOwnPtr<GL::GLContext> context, WebGLContextAttributes context_creation_parameters, WebGLContextAttributes actual_context_parameters)
diff --git a/Userland/Libraries/LibWeb/WebIDL/DOMException.cpp b/Userland/Libraries/LibWeb/WebIDL/DOMException.cpp
index 8304b2c3a59..baaeac3a3f7 100644
--- a/Userland/Libraries/LibWeb/WebIDL/DOMException.cpp
+++ b/Userland/Libraries/LibWeb/WebIDL/DOMException.cpp
@@ -11,12 +11,12 @@ namespace Web::WebIDL {
 
 JS::NonnullGCPtr<DOMException> DOMException::create(JS::Realm& realm, DeprecatedFlyString const& name, DeprecatedFlyString const& message)
 {
-    return realm.heap().allocate<DOMException>(realm, realm, name, message).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<DOMException>(realm, realm, name, message);
 }
 
 JS::NonnullGCPtr<DOMException> DOMException::construct_impl(JS::Realm& realm, DeprecatedFlyString const& message, DeprecatedFlyString const& name)
 {
-    return realm.heap().allocate<DOMException>(realm, realm, name, message).release_allocated_value_but_fixme_should_propagate_errors();
+    return realm.heap().allocate<DOMException>(realm, realm, name, message);
 }
 
 DOMException::DOMException(JS::Realm& realm, DeprecatedFlyString const& name, DeprecatedFlyString const& message)
diff --git a/Userland/Libraries/LibWeb/WebSockets/WebSocket.cpp b/Userland/Libraries/LibWeb/WebSockets/WebSocket.cpp
index 6699af290c8..d5050e70e38 100644
--- a/Userland/Libraries/LibWeb/WebSockets/WebSocket.cpp
+++ b/Userland/Libraries/LibWeb/WebSockets/WebSocket.cpp
@@ -53,7 +53,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<WebSocket>> WebSocket::construct_impl(JS::R
 {
     auto& vm = realm.vm();
 
-    auto web_socket = MUST_OR_THROW_OOM(realm.heap().allocate<WebSocket>(realm, realm));
+    auto web_socket = realm.heap().allocate<WebSocket>(realm, realm);
     auto& relevant_settings_object = HTML::relevant_settings_object(*web_socket);
 
     // 1. Let baseURL be this's relevant settings object's API base URL.
@@ -264,13 +264,13 @@ void WebSocket::on_open()
     // 1. Change the readyState attribute's value to OPEN (1).
     // 2. Change the extensions attribute's value to the extensions in use, if it is not the null value. [WSP]
     // 3. Change the protocol attribute's value to the subprotocol in use, if it is not the null value. [WSP]
-    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::open).release_value_but_fixme_should_propagate_errors());
+    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::open));
 }
 
 // https://websockets.spec.whatwg.org/#feedback-from-the-protocol
 void WebSocket::on_error()
 {
-    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error).release_value_but_fixme_should_propagate_errors());
+    dispatch_event(DOM::Event::create(realm(), HTML::EventNames::error));
 }
 
 // https://websockets.spec.whatwg.org/#feedback-from-the-protocol
@@ -282,7 +282,7 @@ void WebSocket::on_close(u16 code, String reason, bool was_clean)
     event_init.was_clean = was_clean;
     event_init.code = code;
     event_init.reason = reason;
-    dispatch_event(HTML::CloseEvent::create(realm(), HTML::EventNames::close, event_init).release_value_but_fixme_should_propagate_errors());
+    dispatch_event(HTML::CloseEvent::create(realm(), HTML::EventNames::close, event_init));
 }
 
 // https://websockets.spec.whatwg.org/#feedback-from-the-protocol
@@ -295,7 +295,7 @@ void WebSocket::on_message(ByteBuffer message, bool is_text)
         HTML::MessageEventInit event_init;
         event_init.data = JS::PrimitiveString::create(vm(), text_message);
         event_init.origin = url().release_value_but_fixme_should_propagate_errors();
-        dispatch_event(HTML::MessageEvent::create(realm(), HTML::EventNames::message, event_init).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(HTML::MessageEvent::create(realm(), HTML::EventNames::message, event_init));
         return;
     }
 
@@ -307,7 +307,7 @@ void WebSocket::on_message(ByteBuffer message, bool is_text)
         HTML::MessageEventInit event_init;
         event_init.data = JS::ArrayBuffer::create(realm(), message);
         event_init.origin = url().release_value_but_fixme_should_propagate_errors();
-        dispatch_event(HTML::MessageEvent::create(realm(), HTML::EventNames::message, event_init).release_value_but_fixme_should_propagate_errors());
+        dispatch_event(HTML::MessageEvent::create(realm(), HTML::EventNames::message, event_init));
         return;
     }
 
diff --git a/Userland/Libraries/LibWeb/XHR/FormData.cpp b/Userland/Libraries/LibWeb/XHR/FormData.cpp
index 31523e199b5..86d05ad72a7 100644
--- a/Userland/Libraries/LibWeb/XHR/FormData.cpp
+++ b/Userland/Libraries/LibWeb/XHR/FormData.cpp
@@ -35,7 +35,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<FormData>> FormData::construct_impl(JS::Rea
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<FormData>> FormData::construct_impl(JS::Realm& realm, Vector<FormDataEntry> entry_list)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<FormData>(realm, realm, move(entry_list)));
+    return realm.heap().allocate<FormData>(realm, realm, move(entry_list));
 }
 
 FormData::FormData(JS::Realm& realm, Vector<FormDataEntry> entry_list)
diff --git a/Userland/Libraries/LibWeb/XHR/FormDataIterator.cpp b/Userland/Libraries/LibWeb/XHR/FormDataIterator.cpp
index 64e6395ea7c..b27856f53b0 100644
--- a/Userland/Libraries/LibWeb/XHR/FormDataIterator.cpp
+++ b/Userland/Libraries/LibWeb/XHR/FormDataIterator.cpp
@@ -15,7 +15,7 @@ namespace Web::Bindings {
 template<>
 void Intrinsics::create_web_prototype_and_constructor<FormDataIteratorPrototype>(JS::Realm& realm)
 {
-    auto prototype = heap().allocate<FormDataIteratorPrototype>(realm, realm).release_allocated_value_but_fixme_should_propagate_errors();
+    auto prototype = heap().allocate<FormDataIteratorPrototype>(realm, realm);
     m_prototypes.set("FormDataIterator"sv, prototype);
 }
 
@@ -23,9 +23,9 @@ void Intrinsics::create_web_prototype_and_constructor<FormDataIteratorPrototype>
 
 namespace Web::XHR {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<FormDataIterator>> FormDataIterator::create(FormData const& form_data, JS::Object::PropertyKind iterator_kind)
+JS::NonnullGCPtr<FormDataIterator> FormDataIterator::create(FormData const& form_data, JS::Object::PropertyKind iterator_kind)
 {
-    return MUST_OR_THROW_OOM(form_data.heap().allocate<FormDataIterator>(form_data.realm(), form_data, iterator_kind));
+    return form_data.heap().allocate<FormDataIterator>(form_data.realm(), form_data, iterator_kind);
 }
 
 FormDataIterator::FormDataIterator(Web::XHR::FormData const& form_data, JS::Object::PropertyKind iterator_kind)
diff --git a/Userland/Libraries/LibWeb/XHR/FormDataIterator.h b/Userland/Libraries/LibWeb/XHR/FormDataIterator.h
index e07f846c04a..cc02aac6e10 100644
--- a/Userland/Libraries/LibWeb/XHR/FormDataIterator.h
+++ b/Userland/Libraries/LibWeb/XHR/FormDataIterator.h
@@ -15,7 +15,7 @@ class FormDataIterator : public Bindings::PlatformObject {
     WEB_PLATFORM_OBJECT(FormDataIterator, Bindings::PlatformObject);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<FormDataIterator>> create(FormData const&, JS::Object::PropertyKind iterator_kind);
+    [[nodiscard]] static JS::NonnullGCPtr<FormDataIterator> create(FormData const&, JS::Object::PropertyKind iterator_kind);
 
     virtual ~FormDataIterator() override;
 
diff --git a/Userland/Libraries/LibWeb/XHR/ProgressEvent.cpp b/Userland/Libraries/LibWeb/XHR/ProgressEvent.cpp
index 83c7ecdf271..0fa831b13e3 100644
--- a/Userland/Libraries/LibWeb/XHR/ProgressEvent.cpp
+++ b/Userland/Libraries/LibWeb/XHR/ProgressEvent.cpp
@@ -9,9 +9,9 @@
 
 namespace Web::XHR {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<ProgressEvent>> ProgressEvent::create(JS::Realm& realm, FlyString const& event_name, ProgressEventInit const& event_init)
+JS::NonnullGCPtr<ProgressEvent> ProgressEvent::create(JS::Realm& realm, FlyString const& event_name, ProgressEventInit const& event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<ProgressEvent>(realm, realm, event_name, event_init));
+    return realm.heap().allocate<ProgressEvent>(realm, realm, event_name, event_init);
 }
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<ProgressEvent>> ProgressEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, ProgressEventInit const& event_init)
diff --git a/Userland/Libraries/LibWeb/XHR/ProgressEvent.h b/Userland/Libraries/LibWeb/XHR/ProgressEvent.h
index 285d2480c88..5f8c24de90d 100644
--- a/Userland/Libraries/LibWeb/XHR/ProgressEvent.h
+++ b/Userland/Libraries/LibWeb/XHR/ProgressEvent.h
@@ -24,7 +24,7 @@ class ProgressEvent final : public DOM::Event {
     WEB_PLATFORM_OBJECT(ProgressEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<ProgressEvent>> create(JS::Realm&, FlyString const& event_name, ProgressEventInit const& event_init);
+    [[nodiscard]] static JS::NonnullGCPtr<ProgressEvent> create(JS::Realm&, FlyString const& event_name, ProgressEventInit const& event_init);
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<ProgressEvent>> construct_impl(JS::Realm&, FlyString const& event_name, ProgressEventInit const& event_init);
 
     virtual ~ProgressEvent() override;
diff --git a/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp b/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp
index 116d9048c45..fae5c8e3835 100644
--- a/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp
+++ b/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp
@@ -51,11 +51,11 @@ namespace Web::XHR {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<XMLHttpRequest>> XMLHttpRequest::construct_impl(JS::Realm& realm)
 {
-    auto upload_object = MUST_OR_THROW_OOM(realm.heap().allocate<XMLHttpRequestUpload>(realm, realm));
+    auto upload_object = realm.heap().allocate<XMLHttpRequestUpload>(realm, realm);
     auto author_request_headers = Fetch::Infrastructure::HeaderList::create(realm.vm());
     auto response = Fetch::Infrastructure::Response::network_error(realm.vm(), "Not sent yet"sv);
     auto fetch_controller = Fetch::Infrastructure::FetchController::create(realm.vm());
-    return MUST_OR_THROW_OOM(realm.heap().allocate<XMLHttpRequest>(realm, realm, *upload_object, *author_request_headers, *response, *fetch_controller));
+    return realm.heap().allocate<XMLHttpRequest>(realm, realm, *upload_object, *author_request_headers, *response, *fetch_controller);
 }
 
 XMLHttpRequest::XMLHttpRequest(JS::Realm& realm, XMLHttpRequestUpload& upload_object, Fetch::Infrastructure::HeaderList& author_request_headers, Fetch::Infrastructure::Response& response, Fetch::Infrastructure::FetchController& fetch_controller)
@@ -100,7 +100,7 @@ static void fire_progress_event(XMLHttpRequestEventTarget& target, FlyString con
     event_init.loaded = transmitted;
     event_init.total = length;
     // FIXME: If we're in an async context, this will propagate to a callback context which can't propagate it anywhere else and does not expect this to fail.
-    target.dispatch_event(*ProgressEvent::create(target.realm(), event_name, event_init).release_value_but_fixme_should_propagate_errors());
+    target.dispatch_event(*ProgressEvent::create(target.realm(), event_name, event_init));
 }
 
 // https://xhr.spec.whatwg.org/#dom-xmlhttprequest-responsetext
@@ -179,8 +179,8 @@ WebIDL::ExceptionOr<JS::Value> XMLHttpRequest::response()
     // 6. Otherwise, if this’s response type is "blob", set this’s response object to a new Blob object representing this’s received bytes with type set to the result of get a final MIME type for this.
     else if (m_response_type == Bindings::XMLHttpRequestResponseType::Blob) {
         auto mime_type_as_string = TRY_OR_THROW_OOM(vm, TRY_OR_THROW_OOM(vm, get_final_mime_type()).serialized());
-        auto blob_part = TRY(FileAPI::Blob::create(realm(), m_received_bytes, move(mime_type_as_string)));
-        auto blob = TRY(FileAPI::Blob::create(realm(), Vector<FileAPI::BlobPart> { JS::make_handle(*blob_part) }));
+        auto blob_part = FileAPI::Blob::create(realm(), m_received_bytes, move(mime_type_as_string));
+        auto blob = FileAPI::Blob::create(realm(), Vector<FileAPI::BlobPart> { JS::make_handle(*blob_part) });
         m_response_object = JS::Value(blob.ptr());
     }
     // 7. Otherwise, if this’s response type is "document", set a document response for this.
@@ -434,7 +434,7 @@ WebIDL::ExceptionOr<void> XMLHttpRequest::open(String const& method_string, Stri
         m_state = State::Opened;
 
         // 2. Fire an event named readystatechange at this.
-        dispatch_event(TRY(DOM::Event::create(realm(), EventNames::readystatechange)));
+        dispatch_event(DOM::Event::create(realm(), EventNames::readystatechange));
     }
 
     return {};
@@ -684,7 +684,7 @@ WebIDL::ExceptionOr<void> XMLHttpRequest::send(Optional<DocumentOrXMLHttpRequest
 
             // 5. Fire an event named readystatechange at this.
             // FIXME: We're in an async context, so we can't propagate the error anywhere.
-            dispatch_event(*DOM::Event::create(this->realm(), EventNames::readystatechange).release_value_but_fixme_should_propagate_errors());
+            dispatch_event(*DOM::Event::create(this->realm(), EventNames::readystatechange));
 
             // 6. If this’s state is not headers received, then return.
             if (m_state != State::HeadersReceived)
@@ -1086,7 +1086,7 @@ WebIDL::ExceptionOr<void> XMLHttpRequest::handle_response_end_of_body()
 
     // 9. Fire an event named readystatechange at xhr.
     // FIXME: If we're in an async context, this will propagate to a callback context which can't propagate it anywhere else and does not expect this to fail.
-    dispatch_event(*DOM::Event::create(realm, EventNames::readystatechange).release_value_but_fixme_should_propagate_errors());
+    dispatch_event(*DOM::Event::create(realm, EventNames::readystatechange));
 
     // 10. Fire a progress event named load at xhr with transmitted and length.
     fire_progress_event(*this, EventNames::load, transmitted, length);
@@ -1138,7 +1138,7 @@ JS::ThrowCompletionOr<void> XMLHttpRequest::request_error_steps(FlyString const&
 
     // 5. Fire an event named readystatechange at xhr.
     // FIXME: Since we're in an async context, this will propagate to a callback context which can't propagate it anywhere else and does not expect this to fail.
-    dispatch_event(*DOM::Event::create(realm(), EventNames::readystatechange).release_value_but_fixme_should_propagate_errors());
+    dispatch_event(*DOM::Event::create(realm(), EventNames::readystatechange));
 
     // 6. If xhr’s upload complete flag is unset, then:
     if (!m_upload_complete) {
diff --git a/Userland/Libraries/LibWeb/XML/XMLDocumentBuilder.cpp b/Userland/Libraries/LibWeb/XML/XMLDocumentBuilder.cpp
index c80472ad2ef..668e2bb2ea3 100644
--- a/Userland/Libraries/LibWeb/XML/XMLDocumentBuilder.cpp
+++ b/Userland/Libraries/LibWeb/XML/XMLDocumentBuilder.cpp
@@ -197,7 +197,7 @@ void XMLDocumentBuilder::document_end()
         document->load_timing_info().dom_content_loaded_event_start_time = HighResolutionTime::unsafe_shared_current_time();
 
         // Fire an event named DOMContentLoaded at the Document object, with its bubbles attribute initialized to true.
-        auto content_loaded_event = DOM::Event::create(document->realm(), HTML::EventNames::DOMContentLoaded).release_value_but_fixme_should_propagate_errors();
+        auto content_loaded_event = DOM::Event::create(document->realm(), HTML::EventNames::DOMContentLoaded);
         content_loaded_event->set_bubbles(true);
         document->dispatch_event(content_loaded_event);
 
@@ -237,7 +237,7 @@ void XMLDocumentBuilder::document_end()
         // Fire an event named load at window, with legacy target override flag set.
         // FIXME: The legacy target override flag is currently set by a virtual override of dispatch_event()
         // We should reorganize this so that the flag appears explicitly here instead.
-        window->dispatch_event(DOM::Event::create(document->realm(), HTML::EventNames::load).release_value_but_fixme_should_propagate_errors());
+        window->dispatch_event(DOM::Event::create(document->realm(), HTML::EventNames::load));
 
         // FIXME: Invoke WebDriver BiDi load complete with the Document's browsing context, and a new WebDriver BiDi navigation status whose id is the Document object's navigation id, status is "complete", and url is the Document object's URL.
 
diff --git a/Userland/Services/WebContent/WebContentConsoleClient.cpp b/Userland/Services/WebContent/WebContentConsoleClient.cpp
index 1f32d541881..da80cdd9ab5 100644
--- a/Userland/Services/WebContent/WebContentConsoleClient.cpp
+++ b/Userland/Services/WebContent/WebContentConsoleClient.cpp
@@ -28,7 +28,7 @@ WebContentConsoleClient::WebContentConsoleClient(JS::Console& console, JS::Realm
     , m_client(client)
 {
     auto& window = verify_cast<Web::HTML::Window>(realm.global_object());
-    m_console_global_environment_extensions = realm.heap().allocate<ConsoleGlobalEnvironmentExtensions>(realm, realm, window).release_allocated_value_but_fixme_should_propagate_errors().ptr();
+    m_console_global_environment_extensions = realm.heap().allocate<ConsoleGlobalEnvironmentExtensions>(realm, realm, window);
 }
 
 void WebContentConsoleClient::handle_input(DeprecatedString const& js_source)
diff --git a/Userland/Services/WebContent/WebDriverConnection.cpp b/Userland/Services/WebContent/WebDriverConnection.cpp
index d59642278a1..ead63a00381 100644
--- a/Userland/Services/WebContent/WebDriverConnection.cpp
+++ b/Userland/Services/WebContent/WebDriverConnection.cpp
@@ -316,7 +316,7 @@ static bool fire_an_event(FlyString name, Optional<Web::DOM::Element&> target)
     if (!target.has_value())
         return false;
 
-    auto event = T::create(target->realm(), name).release_value_but_fixme_should_propagate_errors();
+    auto event = T::create(target->realm(), name);
     return target->dispatch_event(event);
 }