I would love to use Firefox exclusively on my Mac, but I also like a long lasting battery. Because of https://bugzilla.mozilla.org/show_bug.cgi?id=1941693 Firefox currently uses twice as much CPU during YouTube video playback than even Chrome when you have ProMotion (120 Hz) enabled, significantly reducing battery lifetime. Switching to a different browser every time I want to play a longer YouTube video also isn't the best user experience.
Tell me about it. My old MacBook Pro was only getting like 3-4 hours of battery life with FF.
Firefox is not an upgrade from either Chrome or Safari.