Outside the "everything's always fine" echo-chamber, the consensus is that easily created fiat currencies will all evaporate as the temptation to continue printing/borrowing money into existence is irresistible: the only way to keep the system from imploding is to devalue the soaring debt and interest payments with inflation, and the dial controlling inflation is money-printing / central banks buying debt and all the related tricks.

The problem is that once the dial is turned to 11, inflationary expectations start feeding back into real-world inflation and inflation then escapes the control of central bankers and government treasuries: creating more money to devalue the currency and service the debt ends up destroying the currency via hyper-inflation.

History offers many examples of this temptation and dynamic. The pain of debts being written off, governments defaulting on bonds and assets crashing is too great, and so we have to print more money / borrow more money into existence to stave off the painful reckoning of debt dependence and central bank hubris.

To stave off the pain of debt saturation / over-indebtedness, monetary authorities collapse the currency and the economy it supported, unleashing maximum pain on everyone who used the currency or owned assets denominated in the currency.

A new dollar is then introduced at a ratio of 1 new unit to 100, or 1,000, or 100,000 of the old dollars. Everyone's financial wealth is wiped out. Tools, skills, precious metals, buildings, mines, farms, etc., still retain their intrinsic / productive value, but the monetary reset means everyone whose phantom wealth was a form of debt is wiped out.