Why do you think you need the complication of blockchain for people to pay for art?
Also a technicality but they’re paying for the NFT of the art not the art itself and some fees, which is not optimal.
a) it's working, at least for now, and it certainly wasn't before (music label owner here, friends with many professional artists)
b) decentralization really does have a few important use case advantages — one can use the asset all across the internet while exhibiting provenance, etc.
Does this include the people whose art is simply downloaded off Deviantart to be sold by a third party as an NFT? Doesn't sound like it's working to me, especially if you consider these things aren't even used enough to be relevant.
But on the subject of piracy, it is still pretty rampant even on major platforms like YouTube, to this day — but less so than when they started out. Very fair to expect a similar trend here.