Firefox on Android has been solid for me, perhaps it's an extension issue? I've definitely run into extension issues on mobile that don't exist on desktop.

I also only run two: Dark Reader, and uBlock Origin. It's uBlock that I find causes rendering issues on some releases of the Android app, but I haven't seen that happen in a while.

The only thing I do find painful was the app redesign removing the feature to clear all tabs on close-swiping the app. You can clear all tabs by selecting 'Quit' from the menu, but it's a hassle. I wish we could drop the forced tab persistence when closing the app as a setting, like used to be the case.