My Notebook's fan starts spinning quite annoyingly because youtube does vp9.
Just for comfort I prefer hardware decoding.
'media.webm.enabled' set to 'false' in Firefox's about:config will disable VP8 and VP9, gracefully falling back to (hardware accelerated) MP4 in almost all cases. This will break .webm and .webp images though.
Could there be some way to only disable webm on youtube? Disabling webm for all of the web just because it makes youtube annoying seems unfortunate.
There's an addon called h264ify that does just that. To test if it's working, go to https://www.youtube.com/html5 and 'WebM VP8' and 'MSE & WebM VP9' are unchecked. Alternately, go to any youtube video and right click->stats for nerds.
what percent of desktops are laptops?
Agreed, and I bet AV1 is really heavy on CPU.
Right now 30% of the global market uses AV1 enabled Chrome and Firefox on desktops.