An NFT has no fundamental value. Its selling price is only worth what someone is willing to pay for it. It reminds me of Tulipmania where something worth next to nothing suddenly sells for a fortune.
AFAIC, this is just a new version of pump and dump and I wouldn't be surprised if the bubble pops. That is, assuming the Greater Fool Theory doesn't prevail and affluent investors persist in paying a fortune for the novelty of owning something worthless.
The greater fool theory argues that prices go up because people are able to sell overpriced securities to a "greater fool," whether or not they are overvalued. That is, of course, until there are no greater fools left.