The US dollar may have been around since the end of their civil war, but every country has had currency since forever. The Romans had currency and the Egyptians before that. The duration of a currency is not what is at stake atm.
At the end of WW2, the UK was broke. But up until that point the UK currency was the global standard.
The adoption of the US dollar only happened after WW2. So in effect a duration of ~74 years.
When the history is checked and the global banking cartel is understood the big picture emerges clearer.
Crypto only started 10 years ago with BTC. But it is only in the last 2-3 years that any sort of volume has been seen, before that is was a hobbyist thing, 10,000 BTC for a pizza?
So in reality BTC has in just a few short 2-3 years, spurred an entire industry to evolve.
We now have, distributed databases, logistics systems, gaming platforms, the basis for a new internet, and of course replacements for institutional money transfers XRP, and of course 'money'.
Digital 'money', be it fiat or crypto only has one difference, ownership of the system. Which takes us back to the global bankers, false flag events that created wars, WW1, WW2, Vietnam, Korean, Gulf and many others. All promoted, with the propaganda controlled by the cartel.
Crypto is real, it is distributed, and it has made huge strides in global awareness. It is the genie that won't be going back in the bottle.
The only question is how long and what will it take before the banking cartel admit defeat?
Maybe they just did by signing over swift to XRP.
https://coingape.com/dolalr-battle-bitcoin-foreign-currency/