The trouble is, gold is no longer a largely "useless" metal any more. Back in the day, gold had few industrial purposes and, by and large, was used as a store of wealth only - jewelry and etc is, for the most part, just a peculiar method of displaying, and transporting, one's wealth.
But nowadays there are substantial industrial uses for the metal that compete for access to the limited quantities with those who would use it as a store of value. That means that, without regard to whether it was an adequate store of value before, it is no longer adequate.
Furthermore, for a store of value to be useful, it must grow - and shrink - in accordance with the actual wealth in the world; that is, as value is added, the amount of storage medium available to represent that value must grow; furthermore, as value shrinks in a contracting economy, the amount of storage medium available must also shrink.
Gold is not capable of that required level of elasticity, if it ever was.
Further, a new discovery of a significant new supply of gold blows an inflationary hole in the economy because all of a sudden there is too much money - i.e., gold - chasing the same amount of goods. This happened, for example, when the Spanish started bringing gold back from the Americas.
Gold is not, if it ever was, a good store of value.
