This is very closed minded perspective; having a distributed ledger of digital collectable assets that you can trade without being tied to one exchange or marketplace is powerful and the beginning of the end of institutional gate keeping.

The blockchain is the public ledger, where the ownership message is stored. The CA simply verifies that the message is actually from the artist.

Tangentially, perhaps the blockchain could be turned into the official registry of the CA, too. Wouldn't that be better than a privately managed database somewhere?

I think a global decentralized trusted ledger will become an important thing in the future (whether NFTs specifically are a legit use case or not).