[vkou]

Even in the worst case scenario, a 100% haircut sounds incredibly unlikely.

Unless you actively elect a government that pursues such a policy. Or unless someone somehow puts all that money in a large bag, and flies off to Cyprus (If that's a real concern in your society, there is no guarantee that your brokerage or bank won't do something similar). Bad governance and theft can ruin anything, just ask anyone who has lived in 90s Russia - where the government could not hold up it's end of the social contract, but neither could any of the thousands of thieves and fraudsters that spun up in the privatized financial sector.

As it turns out, when the economy collapses to the point that a government can't[1] pay it's bills, everything else goes to shit, too.

---

[1] The budget brinkmanship the Republican party practices every year isn't a matter of 'cant' - it's a matter of 'politically expedient to pretend that they wont'. But that cycles back to not electing people who govern poorly...

[Ekaros]

100% hair cut leads to violent revolutions. And 70 year old can still do some things that will hurt those in power.