They all claim to be anonymous. And yeah, nobody can independently validate the no logs policy, even Mullvad that has been security audited doesn’t let anyone near their production environment, so what they release to the testers might not be identical to what they use live.

Calling TOR anonymous is a big stretch through, a bunch of commits to the code have been traced back to the CIA if I remember correctly, and various intelligence agencies worldwide are running exit nodes and log everything they can get their hands on. Whether they can decrypt it with current tech is another story, but you better believe they don’t just delete it.