...
But what pre-dominates monetary history is choice. When a critical mass of people use something as money, that thing becomes money. It's as simple as that.
I would agree with that statement if you would include a condition that the "something that people use as money" must be scarce.
If you take a look into monetary history you will see that things like shells were only used as a medium of exchange in regions
where shells were incredibly scarce (= hundreds of miles away from the next shore). Consequently, shells would have been
useless in regions where shells are found in abundance and therefore they never gained any traction as a medium of exchange
in these parts of the world.
This is also one of the reasons why gold continues to store value after thousands of years. Even if the annual global output of gold would be doubled, the impact
on the global supply would be negligible (the current annual output of gold is not even 2 % of the already distributed supply). Obviously, it is
incredibly difficult to ramp up the mining of gold, because resources are scarce and often located in politically unstable parts of the world.