If you're holding maybe you don't think you've lost money yet - but you spent a bunch of money on 0s and 1s and no one is going to buy those from you.
If somebody decided their NFT was worthless they could burn it or sell it for almost nothing and declare a loss they can write off on their taxes. If you bought a bored ape for $100,000 you could get $15,000 or more in tax write-offs. When people have really given up on NFTs you will see tax loss harvesting.