Like many bitcoin enthusiasts and libertarians you don’t really understand how modern money works. That’s understandable so I’m not having a go at you. Let me help.
The currency of the USA is backed by the worlds strongest military and all the assets the USA owns. A small city would likely pay off the government “debt”. I write “debt” because it’s not really debt it’s just the private sector surplus of dollars in circulation. Dollars are spent into existence by the US government. Only after this can they be taxed back to allow some private sector capacity to be purchased by the government for public services like military, police, government etc.
I’m constantly seeing articles about lost bitcoins on medium. I don’t see any articles about banks losing any USD. Bitcoin isn’t backed by anyone so if there’s a world war what would you want? USD in the hand or bitcoins on a USB? I know only hard currency or maybe precious metals are going to be the going currency to buy food. Good luck with the bit coin tulip mania: https://en.m.wikipedia.org/wiki/Tulip_mania