How to know the NFT artist didn’t lie? Central registry required?

NFTs don't actually make sense because the artist can tokenize their art multiple times and lie to the blockchain, and can tokenize it on a different blockchain. This causes the need for a central registry, which eliminates the whole purpose of tokenizing on Ethereum. You also have no legal rights, and an infinite amount of NFTs can/will flood the market (making most illiquid). It makes no sense