Digital art can be recreated easily, which is probably one reason why few people have been paying money for it.

Physical art, which people have historically paid for, is much more difficult to credibly reproduce than NFTs.

Edited to add:

Moreover if the argument in favor of NFTs is that they're not worse than what preceded them, then what's the point of introducing them? If the same problems in the traditional art market (especially for digital works) are recapitulated with NFTs, I don't see the point.