Earlier quoted context omitted.
But the article says that they have no value now. Someone is still buying and selling some of these things, for some reason.
Wash trading is another explanation. When the same person is buying and selling there is no real value being demonstrated.
With Bitcoin or Eth or Doge or whatever, it's hard to paint the tape. You can't move the ticker by selling BTC to yourself at a high price, because your offer to buy it at that price will be rudely filled by somebody else selling their BTC, leaving you holding the bag. Since all BTC is presumed to be equally good you cannot selectively buy only from yourself. The exception to this is of course when you operate an exchange in which case you can fake whatever trading you like.
But with NFTs you don't need to be an exchange operator. Wash trading for everyone! Only YOU hold Bored Ape #1337, only YOU can sell it, so you can safely trade it back and forth between two, three, or a dozen of your own accounts all day giving it the appearance of value while losing only transaction fees. You'll never have your buy offer matched with another seller of Ape #1337 since you have the only one.
All NFT sales should be assumed wash trades without evidence to the contrary.