I think some of his self help stuff was pretty helpful for many people, so he probably is still a net positive

Just remember this applies to almost all snake oil salesmen, evangelists, and fake tv "doctors" like Dr Phil. People just think those are bad because they didn't help them personally, and it looks cringe or exploitative because of that. The same way "clean your room/penis" looks to people who Peterson isn't helpful towards.

Placebo effect means basically any form of self help that isn't actively exploiting you will help, probably immensely.