It used to freeze up a lot; and, then, you lost all tabs, if it did. That's why I'd stopped using it and switched to Chrome, back in the day.

With all the crap Google's doing, I tried Firefox out again something like 5 or 7 years ago and it's now better than what Chrome offers (for me, of course; I'd've probably still switched, anyway, just to deGoogle my life further).

I do find it starts to massively lag when I get to a certain number of tabs/windows; but Chrome doesn't seem to ever shut off my CPU fans under the same level of load so not like it gets a leg up.