The goal isn't necessarily to outright prevent piracy (but obviously they would if they could). But, by keeping such sites constantly changing it prevents sites from gaining notoriety and keeps people who aren't very tech savvy (the majority) away from torrenting. They may get a site they can trust from a friend, but when that site goes down in a month the hope is they just give up. The faster the churn the more normie users can be kept away from piracy.

Jellyfin is pretty great, but still requires the user be on somewhat close terms with someone tech savvy. Torrenting more generally has the (false) perception of being very risky. It's not about stopping people in the know, we aren't good consumers anyway, it's about stopping tech illiterate people.

Don’t waste your time going and manually getting torrents get the *arr stack. I used to be big against the whole idea of pirating but the boycott the us movement started and I jumped back in to the high seas. First I was trying to learn python to write my own scripts to get torrents to download things, I failed missurabrly! But than I found Sonarr and its related apps.