I love Firefox and I'm really thankful for it, but the power consumption is just too high on Mac. Firefox instantly heats up my laptop even with just a single tab open. I like it better than Chrome, but I just can't take the battery/CPU hit for now.
That's weird. I'm working on a MacBook on FireFox 77 with >50 tabs and it's slightly warm at best. I usually am plugged in when doing something like this so I can't comment on battery drain compared to Chrome