This seems to contradict the purpose of banks. You put your money into banks so that you earn a savings rate on the money while the banks puts it to work in the

This seems to contradict the purpose of banks. You put your money into banks so that you earn a savings rate on the money while the banks puts it to work in the economy. Are the piles of money in mattresses really all that much bigger today than they were 30 years ago? Beyond the demographics of the baby boomers, this feels like a non-story to me.