Not sure about the first point, after all with digital art what matters is the NFT since anyone can copy the artifact 1:1 at virtually no cost and no risk. I agree with many that NFTs are best suited for digital worlds but that begs the question: what happens if the game is centralized? They can still prevent you from actually having or using that item, regardless of any proof of ownership.

Re: wash trading, that also happens in the art world with shell companies.