I can't remember Firefox crashing in recent years and that includes times I approached 2000 open tabs. Though after using the same profile for over 5 years now it has trouble remembering the color scheme for whatever reason.
I'd say that's usually a problem with websites and not the browser.
Many websites are just designed with the 80% of most frequent configurations. And when autoplay is disabled, the browser window is too narrow, a special font isn't loaded or a cookie is blocked all bets are off.
I never had Firefox crashes until Ubuntu 21.10 which I think made Firefox a snap, now I get crashes when it tries to load fonts. And I get that colour scheme thing now too.
