Firefox crashes completely at least once a week for me, and tabs crash at least once a day. I had a brand new tab crash the other day, just seconds after I had opened it and visited a text-only site (no JS, no images). I'm running Firefox 92 on up to date Debian on a machine with 64GB of memory; it's not running out of RAM.
I still use it because it's better than Chrome, and I wouldn't touch Brave with a 10 foot pole.