Extensions used to be more capable, this is about to end. Decent side tabs in chrome is called vivaldi, (actually a decent chrome is vivaldi).
Mozilla effectively bans extensions they don't like since the made signed extensions mandatory.
I disagrre on the speed and performance difference, with 150+ tabs opened at all times firefox works while chrome struggle to deal with 50 tabs. All this on a core i5 16GB RAM SSD laptop. I guess YMMV here.