Every empire hyperinflated itself in the past, people just ignore history and how returning to sound money is inevitable.
The only black swan part is that now we have a better alternative to gold.
(just kidding, I know you mean crypto, but its superiority to gold is a bit debatable).
We're they able to get it under control historically?
US was trusted to hold gold in the world wars, but of course Nixon renegged on the gold standard.
Right now people are starting to hold Bitcoin, and it's much harder to take away from them (flying out with a billion dollars of Bitcoin is trivial, as metal detectors won't catch you), so I'm optimistic that the transition will be more peaceful. Also Bitcoin adoption in US is highe than in other countries.
Generally in modern portfolio theory you can just decrease the asset in the portfolio if the volatility is too big for you (for example to just 2% of the portfolio).
I'm 100% in, but for other people I generally suggest it to be 5% of their portfolio.