Without internet they can't have their "banker world government proprietary crypto" + social credit score system either. It got away from them.

In theory the same would be true for any fiat money that's in a bank or stocks or things like that. Perhaps cash could still be used in some ways by people, who knows how such an event would shake out. But if you can't access the cash from the bank or the stocks, you can't use it at all.

I also agree with what others have started that crypto is probably over valued at the moment for what it is, but it's really not that much different from looking at the numbers in your bank account on your phone. If people agree that something has value, then people can exchange it for goods and services.

I'll probably anger a few other people here too, but I don't think gold or silver would really hold their values in such a catastrophe either. They're basically just very shiny metals. People won't be making electronics in such a world, food or a hatchet would be worth more than someone wanting shiny metals for jewelry.

There aren't a whole lot of intrinsic uses for gold or silver outside of electronics and jewelry anymore. So maybe people would trade with it, but a majority of people don't own any gold or silver except what's in their jewelry box. And if people don't have the assets, it can't be a viable currency in the wider community. As I said, food, fuel, generators, hunting equipment, etc would be much more valuable than any shiny metal would be.