Crypto or a fiat created by a more stable and less corrupt government will probably become the new medium regardless of an influx of gold.

The issue with banking isn't gold or fiat. Most libertarians don't get this. The issue is fractional reserve banking. It allows private bankers to control the money supply and effectively drown the country in debt. It creates inflation and it's mathematically impossible to pay back the debt because when considering interest, you will always owe more to the banks than the entire existing stock of money.

It also gives bankers undue profit as they are the first to get access to freshly printed money before the effects of inflation kick in.

That's how the banking class became the dominant faction in Western capital rather than the oil or steel owners.