The other thing I was imagining was that trading a card could just utilize existing nft platforms, instead of the publisher having to set up an ecommerce marketplace for managing card trades.
Although yeah this is definitely more "solution looking for a problem"
Actually the publisher wouldn't even need to have a db full of keys or maintain a catalog of valid NFTs. Authenticity could be proven by just seeing whether the initial owner/issuer of the NFT is the publisher
Just as decentralized of ownership as an NFT lol