I think a lot of it is to just support artists. A kind of charity from universe for artist to continue doing what they are doing. People who are making big money on NFT are already established artists. With physical art, artist sells it once and has no idea where it is. With NFTs, artists can set up royalties for every sale. With block chain, if you can verify address of artist then as a buyer you can guarantee that you are buying original work and also ensures that all (or some during resale) money goes to artist.