The risk calculation is very different. Cryptocurrency is protected by passwords and keys and stuff so is secure from theft without needing a bank. But cash is

The risk calculation is very different. Cryptocurrency is protected by passwords and keys and stuff so is secure from theft without needing a bank. But cash is not, so a bank does provide value - you're more likely to be robbed than the bank go under. And of course, in most places, banks and other institutions are protected with rules about keeping a certain amount of cash on hand and some sort of insurance mandated by the government.