I was a pretty early adopter of Firefox, when it was Phoenix back in 2003 (version 0.2 or something) and when I switched to Mac in the mid-2000's I stuck with it until around 2010. I still use it for some sites and some situations, but the major reason for me using Safari rather than Firefox is simply battery life. It's not even close.
Even watching a Netflix show, Firefox will consume 2x the power that Safari does on my M1 Max and on my old Intel machine the difference was even worse.
On my work laptop it's a similar story, Edge is just so much more efficient, and often internal web-based applications are not compatible with Gecko, so there's just no reason to use it for work either.
It's a shame, because I think it's objectively a better browser than Safari in terms of flexibility and plugins.
