**Everybody wants gold because everybody else wants gold, and its hard to get.**
I mean, really, that’s the reason it’s so precious.
The real question then, is how did everyone come to want gold so much? Originally it was ornamental – desirable as a demonstration for status. It still is. Most metals served as some sort of barter device in history.
But, we mostly want gold today, because every government in the world has resorted to fiat money (‘confetti and electrons’), and so gold is the only ‘naturally occurring’ currency that everyone understands is a currency. And they understand it because everyone else understands and wants it as a currency – for partly historical reasons: it was part of the balance-of-power system in Europe when Europe had its great leap forward.
After gold, the USA’s currency is more valuable and stable and lower risk, since it’s such a large economy, and has such a large military force, and that large military force controls the sea and air lanes, and as such can dictate the world terms of commerce and trade (to some degree at least) both by trade policy, monetary policy, and strategic policy.
So gold the best currency to flee to when the demand for (value of) the USA’s currency is in doubt. You cant easily make more gold, so it’s not going to lose value until the confidence in some OTHER currency is higher than the confidence they have in the price of gold.
Because, say, If the USA disappeared tomorrow so would the value of all dollars world wide. But not the value of gold. Everyone remaining would still want it. And until some other hegemon arose that gave them the same confidence, gold would remain in high demand at high price.