I like Floorp. it’s a FF fork by a Japanese dev team. Best I can compare it to is Vivaldi as far as customization (what Mozilla will allow).

However the updates for it have been coming less frequently over time so I’m not sure how that bodes for the long term.

But hey i’m currently building my own FF fork with fediverse integration, tree style/stacking tabs, and vim navigation sooooo look forward to that? /shameless self promotion.