Why? If the NFT does not have the creator’s signature - a transaction signed by the creator’s key - why would anyone consider that to be authentic? You can mint

Why? If the NFT does not have the creator’s signature - a transaction signed by the creator’s key - why would anyone consider that to be authentic? You can mint 10 copies of the NFT on 10 different chains, but if the mint transaction is not signed by the creator’s key, it would not be authentic. In the real world, you used to authenticate things through signatures. In the digital world, you would do that by signing transactions with your known wallet.