Oh, Dee. Too many monitors is your problem, or even too much memory. Guaranteed
Firefox would never crash if you used it like regular people do and had only
one monitor and 2GB of memory. Also, I hear Windows EDGE and Explorer are just
bulletproof, and Microsoft also provides an email service, while their lead
guy has a huge charitable non-profit he is running. I also hear that the Linux
kernel is not keeping up with new hardware very well. Sounds like you need big
changes in life!

In all seriousness...

I have an excess of 20 crashes of Firefox per day. It has stopped bothering me.
It still is free software running in a free OS on old hardware.