There is a distinction for multilevel marketing schemes, I believe, that basically says if the majority of the incentive structure is about signing up new people, then it's still a pyramid scheme, even if some token product changes hands.

The law isn't there yet, but NFTs are analogous: There is some putative "art" involved, but it's basically variations of ponzi or pump-and-dump where the value comes from convincing people that the value will be higher later. The fact that something (generously) tangible is involved does not alter the nature of the scheme.

So for that reason, they are not art, the same way some phone card pyramid scheme is not a sales business.