> I don't understand how NFTs change anything, though? Like, why do I care that Bob technically "owns" the file that I have a bit-for-bit identical version of?

Yeah. And Bob just has some blockchain token that signifies nothing, except maybe to enthusiasts of this NFT technology. There's no actual ownership of the file there, not even "technically."

I suppose you could create a Torrens title system that uses NFTs, but all the force will come from the law not the NFT technology.