One thing I find a bit disappointing is that the Sanitizer API is [Exposed=Window] only, so there's no way to use it server-side in Node.js or Deno. A simple sanitize(html: string): string method would have been enough to retire a whole category of npm packages. The irony is that sanitizing untrusted HTML is arguably more common on the server—that's where you receive user input, store it, and render it back.
For now, server-side JavaScript still has to rely on DOMPurify (dragging jsdom along with it) or something like sanitize-html, each shipping its own HTML parser that may subtly disagree with how browsers actually parse markup—which is exactly the problem this API was supposed to solve.