Gold.
> gold has a source of revenue besides the investors; namely, the purchases by consumers like jewelers and industry, who take gold out of the market (2/3 of the production) for uses other than re-sale. When one buys 1 oz of gold, one gets a chip of a metal that one can sell to those consumers, and thus obtain some money that does not come from other investors.
The argument for crypto, etc is the same. There are consumers who want to make purchases, use contracts, etc.