Art doesn't tend to be a good thing to invest in for returns - some artworks become more culturally significant and appreciate, while others fall into obscurity and irrelevance as their style falls out of fashion (see: Damien Hurst). Insurance, sale fees e.t.c. further cut into any kind of return.
What's your point? Art is valuable thus crypto is valuable? I don't think one follows the other.
My point is that, if you break the individual elements that contribute to the value of art, and think about why billionaires buy and sell art, then a lot of those first principles for why value exists, can also be applied to crypto (e.g. scarcity, ease of exchange relative to holding gold at least, a sense of value that isn't tied to practical applications, etc.). And in fact, trading pieces of art around and dealing with physical custody and preservation and forgeries/authenticity and "provenance", just seems to be like an inefficient/clunky physical world blockchain with extra steps and ineffective tokens, if you ask me. So really my point is just that, crypto having some inherent value beyond just tulip mania/pump and dump/greater fool/etc., maybe isn't so weird at all.