Exactly my experience. I'm in a private tracker for books and audiobooks that sometimes has content that's not on other sites (audiobooks, in particular).

I also just joined a different private tracker that specializes in pre-organized .img files pre-loaded for emulation setups. Like, a one-file 1TB image ready to roll with everything preconfigured.

For popular TV/film, private trackers are unnecessary, unless maybe you're very particular about 4K/8K REMUX quality or something more specific.