The history of monetary competition is essentially the history of soft money being continuously replaced by hard money; the one that can better preserve purchasing power over the long term is more likely to become the ultimate currency.

Hard money, with its stronger scarcity and lower supply growth rate, is better suited as a store of value.

Over time, people tend to:
Store wealth in hard money;
Spend soft money that depreciates more easily.

In the long run, wealth will continue to concentrate in hard money.

This actually aligns with the discussion of Gresham's Law and Thiers' Law under different institutional frameworks in economics:
When the law mandates two currencies to circulate at a fixed exchange rate, bad money drives out good money (Gresham's Law).
When people are free to choose their currency, good money tends to gradually dominate (often referred to as Thiers' Law).