That's really sad, because Firefox on Android is actually really great and the fact that you can run addons (e.g. uBlock Origin) makes it even better.
In years past Firefox would occasionally crash on me, but I'm not sure it's ever even done that on my current phone, which is closing in on 9 months old. I'm not exactly treating it kindly either, I currently have 93 "tabs" open and though it doesn't keep those in memory it does recall page position even if it has to reload the original source when I go back (based on it putting me at the same point on the page for a week-old HN thread I was skimming through).
There are some addons I'd recommend bypassing on mobile though just for UI reasons - uMatrix, any of the Vim keybinding options, stuff like that. Also, unfortunately the Invert Colors addon doesn't work on Android because of a missing API.