Firefox using a lot of cpu while playing videos

Which is not true for other distros.
Endeavor os i find arch firefox is as good as chromium browsers

sudo dnf install ffmpeg ffmpeg-libs libva libva-utils

If you have an AMD graphics card (enable rpm-fusion):
sudo dnf swap mesa-va-drivers mesa-va-drivers-freeworld

Intel card:
sudo dnf install intel-media-driver

You can use this Firefox addon to block AV1/VP9 video in Youtube in case your graphics card doesn’t support them

No i have installed this but this does not solve this issue and i find this issue is not present in gnome web. Switching to x11 solve this and i also have inatalled firefox as flatpak issue was same…

Turn off movie lighting in YouTube video settings.
this was a issue and firefox claiming that it has been solved in 112 i need to test

Here is the fix