Meh pay doesn't bother me - that's an internal problem for them. What does bother me is firefox on a mac (2018 15inch pro), it just trashes the battery life. Too many tabs open and the fans go haywire, energy usage spikes etc. My mac is at 140 cycles with approx 72% of the design capacity of the battery left, I'm convinced this is because of firefox's bad performance. Might not be but it's the biggest suspect.
I've been using firefox since the really early days and I eventually gave up on mac and started using Brave. Still use it on windows work machines or occasionally on ubuntu where it doesn't have these problems.
piggybacking on this, the performance of Firefox on a Mac with a 4k external screen is abysmal. any action at all takes an extra second or two to perform. not to mention that if i start watching a youtube video it makes the fans go crazy.
i changed back to chrome because of this and it's so much smoother.
I've been using firefox since the really early days and I eventually gave up on mac and started using Brave. Still use it on windows work machines or occasionally on ubuntu where it doesn't have these problems.