What do you mean "there's no failing for a country with a sovereign currency"? There are many, many examples of countries failing. Some of them had sovereign currencies. Sure they can't "run out of money" if they can print more. Along with many more examples of being able to adjust internal values and metrics. This is a very different thing from not being able to fail.
I’ll be clearer. The failure mode that you’re talking about, where debt ratios are so high that a country isn’t able to service its debt, is economically speaking impossible. This isn’t “too big to fail”, it’s the system working as intended.
