You've gotten some good answers kn fingerprinting so I won't repeat that. I will add though: it depends on what you are trying to do. Blending in with Tor or Mullvad Browsers makes you less trackable, but logging into an account immediately breaks that. Brave et al will only fool naive scripts, sure, but telemetry and built in tracking is another battle to fight: you're going to want a privacy browser even if you stand out amongst the sea of Chrome and Edge. The more of us who do make it more normal looking. At the end of the day you are probably going to want two browsers per machine:a logging in browser and an anonymous web search browser. So no it does not negate itself and is worth doing, but has use case limitations. I find it best to block everything possible in Brave but use it as the sign in browser. Not using Brave shields doesn't make you much less recognizable anyway, you'd have to use Chrome for that.

i would go through your privacy settings and delete and turn off everything you can, then if you can, change pii to nonsense burner info and deletethe account. Services like that can sometimes be useful, but not for accounts specifically. Personally I dont use them and send delete requests to people search sites myself.

Tor + VPN is a VERY contentious topic. The one thing not to do is turn on a VPN in the middle of a Tor session. That's agreed upon. VPN before Tor... it can make it harder to find who you are in some ways, but makes you seem more suspicious that you feel the need to do all that. It makes your activity stand out, and it may even be easier to bully your VPN provider into giving up your identity (if they have it from payment info, etc). But that's just if they are monitoring the exit node, so mot particularly likely. Still, I avoid mixing them entirely. Of the two, Tor is more anonymous, but VPN is faster, hides all network activity even outside the browser and is just about required in many places due to stupid age verification laws and similar nonsense. So I like Mullvad Browser + always on VPN, but Tor is a good tool.