They're like minting a commemorative coin celebrating the asset, and only minting a single coin. The coin does not represent ownership of the asset. It's just...a coin. A token. Supposedly, the uniqueness gives it value, but if I decide to record a single fart, that fart is unique, but the uniqueness does not inherently create value.
An NFT for the Mona Lisa caries no benefits or rights, other than saying "I own the NFT for the Mona Lisa". It's inherently worthless, with a supposed value being created from absolutely nothing.
Anyone buying NFTs either doesn't know what they're actually paying for, or thinks they're going to be able to find a greater fool who will eventually be willing to pay more.