If you look at the total value of fiat money in existence, you'll find that the market cap of gold, which is $7 trillion, is minuscule compared to that.

Fiat is valuable because of one thing: legal tender laws. Legal tender is the path of least resistance for any business to operate in because of three reasons:

1. taxes and fines can only be paid in it
2. all entities that have an accounting obligation must do their accounting in it
3. the government requires that you must accept it as a means of repayment of debt or else it will not help you in collecting debt.

Scarcity is key to gold's value proposition. Once gold's scarcity ends, it will go the way of Rai blocks or sea shells as a store of value.