Still thinking about how I feel about that. Right now, people mainly seem to be using it as a sort of proxy for fine art-style exclusivities people already understand.
An NFT isn't a copyright or anything else. It's just a token that has no inherent meaning. Just like any fiat currency. By convention, it embeds an image -- just like a dollar bill has a picture of George.
But why is this a world we want. What benefit did we create by making profile pictures paid for. NFTs represent the worst of capitalism imo.
EIP721 defines the interface to this unique thing. It's nothing more than a set of functions that enable you to transfer it to another account and approve (and revoke) operators to manage it for you.
what makes nfts "good" or "bad" is how it is getting used. I'm implementing an order-book based dex. Every order is a unique thing, implementing ERC721 adds that extra bit of standardized functionality.