When you say "bank," a bank is a building, a set of computers and chairs and things. The bankers are the people running these banks. They're the chief officers, and they push the loans because they don't care if they go bad. For one thing, they may package these bad loans and sell them off to gullible institutional investors.

Today, people are having to spend so much of their money, to acquire a house and to get an education that they don't have enough to spend on goods and services, except by running into yet more debt on their credit cards and other borrowings.

The economy is being run primarily by the banks for their own interest.

Normally, if someone goes bankrupt, you wipe out the debt and get a fresh start. But that's not permitted with student loans. So the effect is to impoverish many graduates with very high debts.

Most people think of the economy as producing goods and services and paying labor to buy what it produces. But a growing part of the economy in every country has been the Finance, Insurance and Real Estate (FIRE) sector, which comprises the rent and interest paid to the economy's balance sheet of assets by debtors and rent payers.

Debts grow and grow. And the more they grow, the more they shrink the economy. When you shrink the economy, you shrink the ability to pay the debts, so it's all an illusion that the system can be saved. The question is, how long are people going to be willing to live in this illusion?

The vast majority of $100 bills are abroad, not in the United States. So yes, of course there's a use here but nowhere near as much as there's a use for $100 bills abroad.