Except they absolutely have. The contemporary art market is exactly what you describe. There's sharks sitting in tanks of embalming fluid being sold for tens of millions of dollars just to be put in storage, and people laundering their money in art investment schemes. The contemporary art market is absolutely an unhealthy social scene of greed and deception.
With crypto, the pollution is built into the system. It's not only being used by the corruption, it is itself rotten. And neither does some of it look nice on walls.
So is the contemporary art world. The contemporary art world is vastly polluting as well. How much GHG do you think is generated to run a museum, or warehouse, transport aircraft, ect, filled with bad contemporary art?
No-one is proposing that contemporary art is some sort of technological breakthrough that will completely revamp society, make everyone rich and change finance for the rest of time.
(Also, I'm sorry, but I do NOT believe that contemporary art consume even a tiny fraction of the power that cryptocurrencies do when nearly all of it sits in a handful of warehouses and never moves, just changes ownership abstractly. You would really need to prove this claim.)
Yes, there are strong parallels between the art market and the NFT market. The main one being that money laundering seems to be the primary purpose of both. But at least art does provide people with some level of subjective enjoyment beyond that.