Don't be like them and generalize everything. Browsers are complex piece of software with many use cases. For mine for example Firefox works great without major issues. It might not be the case for you and that's fine!

There are plenty of people without issues using FireFox (like me). That being said, I'm sure there are those that have issues, so no downvotes from me. It is however better to not generalize like that.

It's literally not. I've seen multiple performance-impacting bugs that people mention, which is a bummer for those users... But none of them happen to me (Pixel 5, android 13) or plenty of other users. Insisting that FF is just hopelessly broken on Android is simply untrue.

It absolutely used to suck performance wise since I used an S4 for about 2 years. Since then, it's been great. As someone who used to dislike the performance, and now loves it, even over chromium stuff, I can safely suggest your oversimplified opinion is without any real basis. Sucks is such a vague word, and I guess it stops you having to detail and rationalise your personal opinion.

It's always been great on the desktop.