I wouldn’t say that. Maybe youtube uses it by default (I don’t know, though) but a lot of other sites still use H264.
And I don’t see AV1 even on the horizon.
A couple of years ago (2?) I tried converting some of my huge H264 video files to AV1 with then up to date ffmpeg. It was horrendously slow. I don’t remember the numbers but I’m pretty sure it was progressing much slower than the clock.