Mismanagement Of Money

I think that debt and taxes are more like their engines of control. They don't really need the interest payments as much as they need for people to have obligations to their system. They have 1000 times more money than anyone can use already, but lending it out and making people follow a schedule of payments is still an essential population management tool. When people are on a hamster wheel of debt service, they behave predictably, and if they don't, the 'debt and taxes' system will swiftly crack the whip on them to remind them.

The elites are a tiny minority, so it is critically important that all money flow through their hands at one point or another- otherwise, the masses would recognize how useless and debilitating they are, and throw them off their backs. For the elites to hold their status, the masses must remain convinced that money requires management and that there must be a designated class placed in charge of money.

 Money does not require management- it requires protection from mismanagement. The quantity of money and the price paid to rent it will find appropriate levels faster if humans ( who will always act in their own narrow self-interest ) are prevented from managing the money supply. No one would even bother managing the money supply unless they saw a way to manipulate it to their own advantage, and clearly, that is what motivates those who do manage it.