If the asset hosting is both immutable then you're guaranteed to always get the thing that you bought from the url your NFT points too. By being "distributed" I think the idea is the immutability is more guaranteed since no one person will be able to control the database.
You are not answering the question posed.
What do you think you are "getting"? Sure, the pointer will always be the same, and the target will always be the same, and you will always have bought that pointer from some other wallet.
Now what? Can I make other pointers to the same target? Can I make a first pointer to a target I did not create? Can I duplicate a target to a new URI and make a pointer to that and sell? Who enforces my ownership rights?
The value of contracts are the enforcability of them, not the properties of the paper. It can be a CNC cut piece of aluminum or a napkin, the contents and the signatures are what's relevant.
To connect this to main issues with NFTs (currently at least):
* A wallet ID will never change, but I could lose my wallet to someone else, thus the immutability of the signage does not guarantee the immutable connection to a person.
* NFTs (afaik) contain a tokenID, tokenURI, baseURI. I guess that can be read as "wallet X signs over this URI which contains an image of the Mona Lisa to wallet Y". Which is entirely different from explicitly stating "wallet X signs over all rights to the Mona Lisa to wallet Y".