I think the best explanation is that NFTs are a very fancy system of provenance (which the art world already takes very seriously).
Lastly, there is no reason for a service provider to issue NFT's. Service providers earns a ton from taxing the market when people trade items, there is no reason for them to give this away by issuing NFT's. Rather every service I've seen issue NFT's did it to sell items that will never be valuable, but that NFT enthusiasts now think will be valuable thanks to the NFT.
Anyway, best case NFT's are just an untaxed market associated with a game or service content. That is the absolutely best case, in what way does that sound novel?
Edit: The untaxed part probably means that governments will shut it down if it becomes too popular. So even less reasons to invest.
Nothing prevents an author from just issuing a lot of duplicate art and claiming they are the original copy.
Except it's fraud and people would likely figure it out over time. That's the exact same scenario as the blockchain except it's even harder for the artist to cheat as everyone can see the blockchain so when the artist makes copies and tries to sell them then everyone can easily see that they are frauds.
>you can't even prove that it at one time pointed to a specific image
Most NFTs use IPFS which uses hashes to uniquely identify files and even if the file disappears from the internet it can be recovered by anyone who still has the original file and be back online.