That said, the current NFT craze is idiotic. As you point out, there's lots of people trying to try external value to a blockchain using what is more or less nothing more than a "super pinky promise". And that's supremely stupid. Today's valuable blockchains have value by themselves. Linking blockchains to external properties, assets, certificates or capabilities is still an ongoing problem. Only after the identity problem is solved and standardized will NFTs linked to external things be worth anything.
They also seem well suited for being able to transfer ownership of physical goods and also transfer things like warranties. With an NFT tied to a serial number, you could ensure only one owner with that serial numbers item can claim warranty coverage, ensure resellers don’t try and pass off something used as new, ensure stolen goods can be tracked as such, etc.
It's a given that at some point this will be tested in a court, with favorable results.