Good question. I think my perception is that finding and using them is a high bar of entry.

And the suspicion that Google doesn't do even a cursory examination would put me off of using anything that isn't independently vetted.

As a Firefox extension user myself, it is pretty crazy what permissions we allow from them. Even with something like uBlock Origin, which I'm sure a lot of people here use, one of the permissions you have to accept is literally "Access your data for all websites". Why are we okay with that?

Well, the alternative is static filter lists like in Safari, which results in a worse experience.

I trust gorhill much more than I trust random ad delivery networks trying to possibly exploit zero-day vulnerabilities.