> Whatever rare NFT you have I can go make a visually identical NFT for <minimum cost of an NFT> and confirm that I own that NFT
Can you sign that NFT with the creator's private key?
Can you sign that NFT with the creator's private key?
That's the point of digital assets, they are fungible by definition because it's a bunch of 1s and 0s, doesn't matter which system you run it on you will get an indistinguishable output.