edit: Really just curious, I'm assuming I'm using it differently.
I run Steam on the same machine (AoE III) with Firefox, LibreOffice Calc open as well and it's just smooth. No overheating or anything.
I find that hard to believe considering no hardware accelerated video playback (although other linux browsers also have the same problem). At the very least, I think that statement needs to be qualified with a "under certain use cases".
https://addons.mozilla.org/en-US/firefox/addon/icloud-bookma...
https://chrome.google.com/webstore/detail/icloud-bookmarks/f...
I think it does tabs, too, but I'm not sure.
I tried through the years, and always ended up with a main browser (Safari or now Firefox) and Chrome as a Google dedicated browser, because the experience would be miserable otherwise. At this point I stopped blaming the other browsers.
I can/could use any of the properties in a pinch, but something would give after a while. The worst offender for me was Meet, a few hours of here and there meetings would trigger weird interface scaling effects, or it just wouldn’t join any new meeting with the screen staying stale. On firefox Bluejeans or Zoom wouldn’t do it, just Meet.