I'm working on a demanding project that has performance as a fundamental requirement. Unfortunately Firefox turned out to be disappointing: audio/video codecs not supported or supported badly, and decidedly poor performance. Chrome instead is decidedly on another level. My opinion is that firefox prefers the road of features, neglecting the care of performance, and maybe this also depends on the fact that Mozilla doesn't have a big company behind it like chrome has google. It's a big problem, because on this road I don't see a great future for firefox, and we would end up on a road of de facto monopoly, which is not good for anyone.

Haven't had any reason to not use firefox since quantum