With real estate, precious metals, oil, wheat, etc., the benefit comes from the things themselves. In other words, owners can use them for housing, making jewelry and electronics, obtaining energy or food, etc.
State governments must plan to make a lot of jewelry then, because otherwise all that gold kept in their coffers wouldn't make sense. It's almost as if fiat currencies have limited value outside of their respective economies, reducing them to activity logs once we talk about international trade.