TL;DR NFTs that point to centralized mutable databases like s3 are a bad idea, but people are working on immutable data storage technologies like IPFS.
At some junction in this chain (as far as I know as an NFT skeptic, to put it mildly), you (want to) pay for ownership of something non-fungible, be it meatspace or digital. So sure, that thing at the IPFS URI might never change, but I can still copy it, or it might not have originated there, or it's some representation of a real world item, where the representation of course can be reproduced.
You've added another layer of immutability, but I have yet to see where that's relevant to anyone who understands what they would be buying, as there are always more layers.
The dark thing about NFTs IMO is that they only seem like they would work in a "world" where everything was locked down and rights-protected to the detriment of the user experience. In other words, all those "layers" where digital ownership could get fuzzy were removed by operating on some aggressive platform or protocol, like a Fortnite style Metaverse without copy + paste, local file storage, or self-hosting.
I really wish IPFS would stop flirting with NFTs. I rather like the technology and it doesn't really have anything to do with NFTs but I'm afraid there will be a stigma attached to it when this thing finally explodes.
One thing I haven't seen anyone mention is that even the thing referenced by the ipfs url must by bit for bit identical. There's no notion of semantic ownership where you can own an image of the Mona Lisa and we can all agree that slightly different versions are still pictures of the Mona Lisa. I can flip one bit and sell that as another NFT. I can even make those changes in the image meta-data so the actual image is bit for bit identical. Also IPFS does not provide unique id's. An image can have multiple IPFS id's. The uniqueness constraint goes the other way, and IPFS id references one and only one unique resource.
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".