Using your reasoning a large number of collectible items should be worthless. What really makes an NFT different from a Pokemon card, a Birkin bag, or even an original Monet? My guess is that the seller has to have some sort of authority and established reputation for these kinds of artificially scarce luxury goods to maintain value.
The big issue with NFT's is that can't use them to flex on people as easily.
> Using your reasoning
Clearly not, the point being made was that you owned a thing, e.g. a Pokemon card. To own an NFT is to, bafflingly, claim to hold a token of ownership of some asset represented by the NFT - where that representation is indicated by the NFT immutably containing, typically, a thoroughly mutable Google Drive link to a picture. The whole thing was always farcical.
Again, at least you actually own the Pokemon card at the end of the day.