Buying a $10M painting is a lot more work than holding $10M in cash, but it does make sense as a store of value given fiat inflation.

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.