Public trackers have the advantage that they often don't even require accounts. If a private site ever gets raided, they'll have a ton of records like everything you've ever seeded, every IP you've used, the email address you signed up with, anything in your profile or comments that could be used to identify you etc. Way more risky than accessing a public website where all they ever see is a random IP address that viewed a page or made a search. If magnet links are available the site won't even have a record of what you actually downloaded.
Yeah and private trackers often ban VPN IPs because it would allow their 'enemies' to get in more easily.
But indeed it means that you are very exposed if the site ever gets taken down. And what we've seen in the netherlands: The site owners often hand everything over when they're caught because they're threatened with huge fines.
There are still pathways into these trackers, which usually require luck or some amount of work on feeder trackers before you get an invite. I got in through the unofficial Reddit tracker BaconBits (RIP) back in the day—YMMV, but it doesn't change the fact that there are better trackers out there.
