Just an update. Firefox 146 just dropped with:

• Firefox now natively supports fractional scaled displays on Linux (Wayland), making rendering more effective.

After upgrading to 146 and natively using Wayland, it feels faster. Some fade animations are still choppier, but on average it’s at least tolerable.

Thanks for the suggestions everyone.

Interesting. I played around with X11 vs Wayland settings just to see what different configurations give me

• MOZ_ENABLE_WAYLAND=1 /snap/bin/firefox - Exhibits low FPS issue
• MOZ_ENABLE_WAYLAND=0 DISABLE_WAYLAND=1 /snap/bin/firefox - Actually feels fast like it should be. Most animations feel faster, some are still choppy though. It’s hard to tell.

It seems like running with X11 sort of the problem? Which seems unexpected and concerns me since I know distros are starting to default to Wayland.

Yep, both are plugged into the graphics card. Other programs and games are a lot faster.