Firefox is out for the same reasons Brave is, I guess, due to the same guy.
Not really a hotbutton issue for me, but your entire screed is predicated on ruling out firefox because the guy WAS there previously. AFAICT that's a bit of a strawman because although he was controversial when he was there, the folks you are railing against for their "purity tests" are not complaining about the influence of that guy on firefox since he's not there anymore.
The answer to your question is "just ignore these concerns that don't matter to you and use what you want" - not sure why that's a reason to be on some kind of soapbox about people who DO care about these things.
No one is going to come check your computer so they can yell at you about whose software you are using. People are just sharing what they see as important info for people to consider. As one does on social media.
Edit: And there's always ungoogled Chromium, but yes that does drive towards a web where no one checks if anything renders correctly on anything but the Chromium base.