Selling the copyright on an image is completely orthogonal to the NFT it is being accompanied with, however. The NFT is only acting as a certificate of ownership saying that someone verifiably possesses the NFT. In my opinion, the NFT bring sold alongside the copyright adds very little value that couldn't already be done pre-blockchains. Courts were perfectly capable of evaluating ownership claims in the past.

And many of these NFTs don't even pretend to sell ownership of any underlying asset. Take Jack Dorsey's tweet, or the burned Banksy artwork for example. When you buy those, you get ownership of exactly 0 actual assets. It's just cashing in on NFTmania (and the larger cryptomania).