Nfts will be enforced by client software in web3.
We've spent the last 20 years decrying how disastrous DRM has been, and now these supposed technologists are trying to sell us on a bold, glorious future where DRM comes knocking for our ability to right-click images.
The process and theory of identifying documents is one of the oldest subjects of interest in library science[1], and the Internet is chock full of unique identification schemes (URIs, nominally, but also OIDs, DOIs, ORCIDs, &c.).
The parts of Xanadu that do exist seem to be mostly "goodfaithware," if you'll excuse the term. It's not clear that they have any real protections (like DRM) against clients copying data and/or not obeying the unique addressing scheme.
Even if that is true, what enforces provenance of art when NFTs are created? False claims of ownership of existing art in the creation of NFTs is a thing; enforcing NFTs doesn't solve the problem if nothing stops NFTs from being frauds ab initio.
when you 'buy' an NFT what you are really buying into is someone else's/a third-party's centralized platform (like opensea or whatever it's called).