It hasn't replaced it. But it does compete with it for some things.

Payments with BTC certainly isn't competitive. But that probably won't last.

Maybe we'll still need branches. Not everybody can deal with the security required for crypto and there will probably be companies that help people treat it like a regular bank.

Inflation is a real issue and Hitler came to power after the hyperinflation in the Weimar republic. Fiat made that possible.

But Germany still would have had to pay the WW1 reparations somehow. With very high taxation probably.

But the hyperinflation happens after multiple years of expanding the currency too much, often with little impact for several years. That can destroy confidence in government in a way that consistently high but stable taxation might not.