This is often repeated, but it always ignores that there are state-level actors (often called a "state") propping up currencies, often supported by central banks. In this regard Bitcoin is definitely not "like any other currency".
This is by no means exhaustive, there are a myriad of differences
Zimbabwe has entered the room. Also had a central bank before the last round of hyperinflation/reset. One could argue that the lack of a central bank is a feature. What other differences would would you imagine distinguish bitcoin from central bank currencies?
“One state is doing terribly” (or even a handful of them, before someone mentions the Weimar republic) really is not equivalent to “it is impossible for a state to do it well”.
This is by no means exhaustive, there are a myriad of differences