“Based on total collapse of the banking system? the stock markets?”
Those are interesting speculations but at this point there’s very little evidence for it.
Repeating the same tired rhetoric doesn’t make it so.
You may think you have money in the bank, but when it closes the doors, you have nothing in the bank. Stock markets panic and everything tumbles down to nothing.
You may have thought you had lots of stocks and securities, but suddenly you have nothing, because a run on the floor wiped the value of your stock to nothing.
Shareholders, brokerage firm traders panic and start selling. This causes a "run" on the banks and businesses, and is what causes them to collapse. Just because banks make billions, remember, that is paid out in dividends to it's shareholders. it doesn't pile up year after year in a giant vault somewhere.