Most of the "value" of gold is by arbitrary societal agreement--there is very low natural use-driven demand compared to the froth from people using it as a store of value. That agreement, in a game theory sense, comes from the original time when participants coalesced around gold because it had the properties that seemed most appealing (limited supply, difficult to fake, measurable, transportable) as a store of value or currency.

Whatever alternatives may arise, the one that will be "most valuable" is the one that everyone thinks everyone else will want.