This is not as much as it looks like at first glance. "Revenue" for the german state is something around $2000B, while their ~3000 tons of gold are worth ~300B.
It is plausible to me that building up a gold reserve might be worth it, longterm, purely because the gained trust/perceived stability nets you slightly better conditions when financing megaprojects alone (like the Fehmarn tunnel): Over a few centuries you might save tax dollars thanks to investing into bigger gold reserves earlier.
And gold is objectively useful if things go to shit-- just look at Russia for a recent example-- gold is nice for mitigating sanctions and stabilizing your currency under bad conditions.
It is plausible to me that building up a gold reserve might be worth it, longterm, purely because the gained trust/perceived stability nets you slightly better conditions when financing megaprojects alone (like the Fehmarn tunnel): Over a few centuries you might save tax dollars thanks to investing into bigger gold reserves earlier.
And gold is objectively useful if things go to shit-- just look at Russia for a recent example-- gold is nice for mitigating sanctions and stabilizing your currency under bad conditions.