How can anyone drop xx million on a painting and not be a money launderer? They're probably a robber baron or tax evader at the very least.
Art in the millions is definitely an exclusive market though, and I'm sure draws various unsavory people.
Buying gold is also easier than buying paintings, and buying gold ETFs is even easier. As is buying stock, bonds, etc. It's easier to hedge societal collapse by buying high value necessities (though who can truly predict how a collapse will unfold).
I think there's a certain kind of person who can be a great art investor by having a good idea of what art is going to retain interest (and thus value), but I would not call it easy compared to index funds or most other popular stores of value.