I looked back repeatedly. For one I could never get it to launch Zoom from a link, it would always try to download the exe again. The Dark Reader extension is much slower on FF than Chrome. I think Chrome is still faster in general, I can tell especially when flipping through a bunch of tabs really fast.
When I came to the realization I was using FireFox essentially just for idealogical reasons I went back to Chrome.
FWIW I use Firefox and zoom with no issues and am really happy with recent updates to the browser. Haven’t tried the dark reader extension though.
Out of curiosity, what's wrong with using a product because you believe in it?
Give Brave a try, it does a lot of things well, and it has some basic independence from Google's direct interests.