I've long suspected that many high-value art sales are a form of money laundering, so it does not surprise me at all to see the idea become blockchain-ified. I wish I'd thought of it first! I expect it will continue to be a resounding success.
Money laundering for sure. But also just a store of value.
A Picasso is like a savings account. You can hold one for decades and it will preserve value relative to inflation so long as people still value them the same.
Another way to think about rare art, is that it is a game. It's a game of trying to predict (or promote) which art will stick long term in some collective consciousness. The Mona Lisa is valuable because literally everyone in the western world knows it. Nyan cat is a modern example. It's a piece of art that is locked into the consciousness of at least tens of millions of younger people who are now starting to have money. If a piece of popular art exists in a form that is ownable and verifyably original, then it will trade for tons of money.
We don't value a copy because machines (or humans acting like machines) can do that for dirt cheap without thought or creative breakthrough.
We value the original.
We value the thing that represents that initial spark of something brand new in the world that latched itself in our collective consciousness. We value that because everyone else values it. It gives people a sense of awe to learn that you own an ORIGINAL Picasso. It's a display of wealth and power, but also tickles something deep and almost spiritual in the human mind.
I wouldn't be surprised if we learn to treat original NFTs the same way for digital art. Maybe first we need good ways of displaying our ownership of them.