I use ArkenFox as a base for a hardened version of FF. It's not really designed to be used verbatim as that would leave the web in a fairly unusable state, at least for most users. I use a fair few overrides because on my daily browser I want it to be able to use DRM content, be able to login to my bank, etc. For me I see it as a really solid foundation, after which I can intentionally pick and choose what functionality to enable at my own risk rather than have bad defaults thrust upon me by the browser vendor.

I personally don't concern myself that heavily with attempting to defend my daily browser's fingerprint. With the default ArkenFox implementation, ResistFingerprinting in FF is enabled and that's the best you can do, but it also breaks a few things on purpose which impacts functionality. I personally have RF off and use the CanvasBlocker extension to defend against naïve fingerprinting scripts, but that's a choice users have to make.

If I were that concerned about being fingerprinted by advanced scripts, I'd be using the Mullvad Browser or TOR. Those are really the only effective way to "blend in" to a crowd. Most any browsers people use as their one for daily use that aren't either of those will be fingerprintable and identifiable by an adversary determined enough, so investing too much time in worrying about a daily browser's fingerprint beyond defending against naïve scripts isn't worth that much time investment, imo.

I prefer librewolf