Well, in the USA, the US govt gave the banks cartel status by giving the Federal Reserve system the effective ability to print up money and loan it out.   In return, the Federal Reserve system makes sure that the interest rates are low enough to always finance government spending.   It was a marriage made in hell.  The thing is, that system will work as long as the system is mostly free market, but when it becomes over saturated with government spending and debt, the market is no longer able to function efficiently, and it starts to eat itself.    

 The real issue is more fundamental, the loaned money is indistinguishable from the “real” money. There is no way to root out leverage because it’s systemic to the money itself. If a bank creates a loan and then deposits from thin air, it’s fundamentally impossible to price it separately according to its counter party risk. Bitcoin fixes this