it's not the same if there is an army and a tax collector that help you 'believe' in a currency.

> when people stop believing in a currencies

That's a foolish comparison. Public servants are paid in the nation's official currency. Do you believe employees just forget about their salary? And I won't even talk about taxes and supplying the state with goods and services.

Equating these so called "cryptocurrencies" with cash is simply idiotic, and something that only serves the agenda of those personally invested in defrauding the world while pumping the bubble.

Faith based currency is a different beast. Money like silver coins can have utility beyond their exchange rate. For example, melted down and used to produce a physical item. You can't do that with paper money or a cryptocurrency.

The utility of silver could still drop, but it's much less likely than someone deciding that a piece of paper or a token in a ledger is essentially worthless.

That said, faith based money can skyrocket in value if everyone believes in it.