My experience is that the performance of videos depends a lot on how much of the screen the video takes up. More so than on the quality setting (480p, 720p, 1080p). Usually when I want to watch a video, I limit it to about 1/4 of the area of my 1920x1080 screen. But YouTube is pretty watchable. I don't think even when you select something like 720p@60fps or whatever that it ever actually gets up to 60fps, and sometimes the parts that don't compress as well drop a few frames (strobing in particular does that), but it's really not bad if you're ok with not doing full-screen.

Also, it depends where the video is hosted. If the JS is really light on the page, it's way more performant. If the JS is really heavy, I sometimes have to wait tens of seconds for it to render the first frame.

But also, this Raspberry Pi is mostly my Lemmy box. Not my main box.