Graeber clearly explained the process of how gold currency appeared in his book (I recommend you to reread Chapter 8: The Axial Age for this). It’s because states needed some convenient medium to provide resources for the military to continue its conquests, and that was precisely what the military was already pillaging from its conquered territory: luxury items made of gold. So the state had to find a way to enforce people to sell other important commodities (such as food and equipment) in exchange for gold, and that made the state to enforce gold coins as a currency in areas near conquests.
You’re right that the social/cultural value associated with those luxury gold collectibles is an important part of the story. But I don’t think you need any other weird evolutionary argument in addition to Graeber’s view to complete the full picture.
You’re right that the social/cultural value associated with those luxury gold collectibles is an important part of the story. But I don’t think you need any other weird evolutionary argument in addition to Graeber’s view to complete the full picture.