Not sure about NFTs... I did hear one interesting thing about NFTs being the pure dilation of "flex". In a similar way that people invest in art that isn't yet famous... it is an investment into the idea that you were "there before it was cool", and that actual "art" is less meaningful. I'm not completely sold on that argument, but there is something to it as well... personally, I invest in art because I like it and I would sort of PREFER that it remained inexpensive and only valuable to me just because I liked the artwork. However, I can see that some other people would invest HOPING it would get more expensive and famous. Different ideas of what is important in life...
Anyway, NFTs don't currently serve the purpose that they purport to serve... they aren't really much of anything without enforcement of some sort of "ownership". Otherwise, they are claims of ownership that anyone can ignore.
However, they do serve as "tickets" to drops or other events... so they do have a use-case there.
In the future, enforceable ownership would be a huge thing... real-estate titles and that sort of thing... but that would require some government recognition. And that I believe, would be sustainable.