They’re extremely good for higher quality content such as 4K REMUX files. I have access to a private tracker that I use regularly. I only search public trackers if what I want isn’t available in the private one…which is rare.
To me it’s not about price or openness or anything. Piracy is a service issue. Private trackers have better service than public trackers. Better curated content, better seeders, and fewer (if any) shit quality re-encodes by people who don’t know what they’re doing.