Heard it a few times and it certainly seems like something that would happen but is there any proof or real world examples?
Can an Appraiser just make something worth $20m based purely on their say so?
EDIT: Thanks some great replies! and yeah i was asking more about the tax evasion part than the 'modern art is bad lol' angle.
Art is a good way for rich people can to launder money or invest money into. I'm really sure if art ever goes down in value, I'm sure it does if the artist gets caught doing something. One of Donald Trumps charities commissioned a painting of himself, and auctioned it off, he won the bid and paid for it will charity money, basically giving himself a painting of himself for free that's probably worth more than both you and me. You can also buy a painting with illicit money, have it sit in an auction house or bank for a couple of years and then anonymously sell it for legitimate money.
Appraisal value is subjective and compared with comparable works on the market. Ultimate it's for insurance and it auction price could radically sell for more. I don't know if people are cheaply paying artists to resale for millions, that usually not what they use art for.
So I have no sources but Ive heard that the rise of NFTs are due to a crack down by the government in money laundering in the art world. Rich people need something to launder their blood money though, and it it's not art or digital art it will be through some other high value asset.
One thing I'll note about this is that art absolutely goes down in value and suffers from the same changes in taste as anything else. Markets get spiked, works get burned, artists aren't as trendy anymore. The really big names will usually pull in big money, but strip away the Sotheby's/Christie's hype machine and works are worth only what someone will pay for, and sometimes that's zero.