I don't disagree that many people are laundering money via NFTs, as I understand that many people also launder money via the purchase of art, and for the most part NFTs are a form of "digital art" (although there is the potential for non-art NFTs).
It is not about art per se. It is about finding a way to "wash" dirty money. Which is why I use the general category of tokens rather than NFTs. It is actually a lot harder and costs a lot of money to launder money using art.
When using tokens, the laundering costs nothing because the creation of the token costs nothing whereas there has to be some art that has some minimum quality to not raise suspicion. The tokens already have no quality and they are not regulated and the "buyer" (who is also the seller putting dirty money from one pocket to another) can be anonymous.
I think there is some underlying value in NFTs.
I don't see it.
I don't think there would be demand for a NFT that could potentially be sold on another blockchain.
Considering the fact that people have bought coins that didn't even have a blockchain (ie. they were dead) mainly during 2017, I don't think they care whether the same NFT is being sold elsewhere!