How little RAM does your phone have? My Moto G4 Power (less than $200, before the RAM crunch much less) with 2 GB runs Firefox hunky-dory, and I'm one of those triple-digit tab people.

It's not about the number of (possibly sleeping) tabs, it's about how FF doesn't manage those active ones to prevent the app from crashing.. try opening 10 instagram profiles (via open in new tab) in the web browser.

I told you all that Chrome doesn't crash, FF does + pages work much slower.

Have you verified what caused the crash via logcat? Firefox has never crashed in my case, not even once (but I'm not running a low ram device).

That was nearly a year ago because chrome with extensions then arrived, but I did verify it was caused by RAM (usage was growing as FF was loading these tabs in background), then I did set some tweak in about:config which made the issue a little less severe (open in new tab didn't start loading them), but it still crashed if I then manually switched tabs, FF did not unload previous ones despite running out of RAM.