I am mostly browser agnostic. So long as it works and doesn't require me to manually maintain it I'll use it. Every time I have tried FF in recent years it was a ball-ache of manual management, crashes, website rendering issues and generally poor performance. No, I haven't tried it for a couple of years, nor have I tried Brave, or any of the other niche browsers recently as every time I test one I spend more time fiddling with the browser than I do browsing the websites.
Chrome has market share because it mostly just works. Yes, it undoubtedly tracks everything I do, but I really don't give a crap about any of that as I never buy anything from their ads. Their "targeted" ads are a joke mostly containing ads for stuff I have already bought, or ads for companies I already rejected when searching for what I want.
Before Chrome I used FF in the early to mid noughties, IE in the late nineties, and Netscape before that. At work I use Chrome and IE (yes, we still have some internal systems that require IE <sigh>). If FF want to take market share away from Google, then they need to produce a browser that is better than Chrome, easier to use than Chrome, more reliable than Chrome, and then they need to keep it that way for long enough for people to switch to it.