[Zanfa]

> I'm more referring to it in the sense of "I trust you to competently administer this database and not tamper with its data"

A well-administered non-tamperable database of garbage data is still quite useless.

With an unpermissioned public blockchain you can make up your own police department, insurance, towing company and repair shops. Make some wash entries to make them look legitimate and you’re back to square one of having to confirm everything off-chain to figure out what’s real.

Or drown a real report in a sea of fakes if you’re trying to offload a lemon, since there’s not much you can do about spam.

Not to mention the fundamental problems around private key management.