NFTs are an evil scam derived from bitcoin and blockchain.
It's using blockchain for proof of ownership, so needs server(s) on the internet. Less durable and environmentally damaging compared to a notarised proof of purchase on acid free paper.
It solves no problems of ownership and creates problems. NFTs and so called Cryptocurrencies should be illegal. Trading or "ownership".
Cryptocurrencies are not currencies, they are speculation vehicles and often pyramid scams. Massively environmentally damaging. Not scaleable. Transaction cost 10,000 more than IBAN. Solves no problems and the claims about fiat currency made to justify crypto-coins only apply to broken governments; arguments by anarchists and criminals.
NFTs are not for reselling digital copies (unless limited edition) as such.
Also with paper or prints of original art in copyright, the publisher can make as many copies as they like. Once the publisher sells the copy, certainly the physical copy can be resold, but the publisher STILL has the copyright. The new owner can resell their copy but not make additional ones.
There are two kinds of NFT:
1) There is only one copy or a limited number of copies (if a digital work), the purchaser can sell on the NFT and the attached work. The purchaser has full copyright on what they bought. They could make copies, but copyright would apply, the purchaser of the copies can't make copies.
2) The NFT creator keeps the copyright. The NFT only applies to the copy the purchaser bought. They can only resell the NFT + copy they bought.
So the NFT is just a bill of sale, an environmentally damaging (because of Blockchain) digital version of a receipt.
https://en.wikipedia.org/wiki/Non-fungible_token