Yes, you're starting to get it. You're not buying art, you're not buying legal rights. If the data was written directly to the blockchain, then it is permanent. But even if it points to some temporary host, big deal, the file itself wasn't the valuable part. Data can endlessly be replicated and rehosted.
It is the genuine provenance of an artist that was bought and traded. It is proof representing a work, whatever that artist declares it to be. They could simply resell it again for all anyone knows, but that would hurt them and devalue all their future work.
All value is abstract.
The papers without the Rolex can be worth anything anyone wants to pay for it. Following that rule I suppose fake papers can even be worth something, but most likely not.
An old Rolex with papers is worth more than without, but the papers without the Rolex are worth nothing. In this case you're just buying the papers.