I would not make that statement so soon. Bitcoin has only existed for 10 years. Most nations and currencies, at least in recent history, have lasted for much longer than that.
That's precisely the weak point of your argument. Give it another 20-30 years and let's then count again how many currencies are still as strong as they were or merely still exist. The USD is in a special place since it's the default currency for worldwide exchanges, so what matters is all other currencies out there.
Almost all currencies backed only by their governments, and not by physical gold, are at most a century old.
The pound sterling of 2019 is more related to the American dollar of 2019 than it is to the pound sterling of even WWII, nonetheless 800CE.
1. USD ~ is markedly different post breaking from gold standard so 40-50 years
2. EUR - created 1999
3. Russian ruble - post fall of Soviet Union.
I mean what’s the standard here? One way or another maybe the longest running one is the British pound but even then, one can easily argue like with the USD that breaking from the gold standard is a different currency altogether. But if “age” is what we’re talking about, it has to be closing in to what the Euro was at on 2009!