It's good, but I have no idea what it does.

its good, but chrome shows error also vivaldi but not brave on downloading from https://github.com/cowlicks/privacypossum why?

It would be necessary to give a little more explanation !
A single phrase lapidary, it does not serve much !

Fortunately there is the GitHub repository, better provided in explanation.
I invite to read it :

https://github.com/cowlicks/privacypossum#current-features

It works and does what is written in its description.

I keep getting facebook ads related to other websites i visit. this is the only reason i got this, and it does nothing.

ok

Very good extension. It does its job, but it would be nice if there was some customizability. I don't like that it breaks embedded YouTube videos. I have it disabled for now, but I'll re-enable it when that's fixed.