WebCodecs is missing. They say it's "worth prototyping" [1] but I don't know whether they are working on it.
[0]https://www.androidpolice.com/mozilla-is-finally-adding-av1-...
That said, I had Clipchamp installed from the MS Store before I went back to MS Video Editor.
Just beware of any major API changes or any indication that it might be dropped in its entirety!