Hyperinflation is extremely uncommon, especially in developed countries, and when it occurs it's always caused by incompetent or corrupt governments, not by the currency itself.
Wishful thinking. Cryptocurrencies have failed to gain traction even in countries experiencing hyperinflation. People don't trust a fiat "currency" that is issued by anonymous entities and is backed by nothing. Especially when it's been known to depreciate dramatically in the blink of an eye. People trust fiat currencies that are issued by reputable institutions that give credible assurances about the purchasing power of said currencies. This is why such currencies as the US dollar and the euro are used all over the world for international trade, and cryptocurrencies are not.
Trust in traditional currency shaken quite significantly in last 3 years. Especially when inflation ruins many businesses and government justify inflation by war and green energy.
When you cannot make living from money that you get from your hard work, naturally, you are forced to look at alternatives. As more people adopt cryptocurrencies, the less value traditional currencies had and eventually ignores inflation. Which, for now, bitcoins does. It just isn't that much popular yet.
No one would expect ten years ago that some cryptocurrency would survive or be adopted by more and more people. But somehow, it's still there and grows every year.
If crypto wouldn't be a thing, there wouldn't be plans for digital Euro by ECB for example. Basically same thing as BTC, except with regulations with centralized bank.
To be clear, I'm not a fan of digital currencies. Cash is still most private and free way of exchange method. For digital, you need electricity, device and data which many cannot afford to have.
So it's just a matter of time when citizens loose trust in fiat currency and start looking for other solutions, like decentralised cryptocurrency.