> > Fiat currencies only end if the issuing entity ceases to exist or abandons them
> I'm curious - can you point to one example of this happening?
Obvious, clear, and fairly recent examples include all of the European currencies that were retired in favor of the Euro.
> To my knowledge they've all gone to zero in a hyperinflation but I'd love to know of a counterexample.
A number have been abandoned (and often replaced by a new currency with the same name) by the issuing state in the face of inflation (often not even at the level typically labelled "hyperinflation"), but the nature of the "fiat" in "fiat currency" essentially assures some minimal residual value as log as the issuing state remains functional as a state and does not abandon the currency.
E.g., the pre-1993 Mexican Peso was withdrawn and replaced by the New Peso after a long period of double-digit annual inflation, but it neither "went to zero" (prior to being withdrawn) nor suffered hyperinflation (monthly inflation >50%.)