The main purpose of money is not to allow people to exchange goods very conveniently, this is just a nice side effect, the main purpose is control and power.
Money may have been an invention to exchange goods and services more easily, but it has been taken over at some point in time or maybe it was taken over from the beginning or even invented as a control mechanism and the other benefits were just there to trick people into using it, historically this is not exactly documented, since money seems to exist for thousands of years. This is also why money is under the occult category, since it has been occulted what it is about.
So if people use money to exchange all of their goods and services, the one who can control the money, then can gain control over all exchange of goods and services. When all goods and services are under control, education and knowledge can be controlled as well and if those are controlled all thinking and all actions of all humans can be controlled as well.
You end up with the ultimate control mechanism as it is able to control everything, only condition is, people have to use it and believe in it, but what people do and believe can be controlled with money, so once the circle is complete there is no way out for the uninitiated masses.
Let me give some examples how it works in reality for those who cannot believe it:
Imagine you or someone else wants to create a business, something big enough so that is able to change the world, what does he need to start it? Of course money, lots of it and how do you get lots of money? Of course from the bank or whoever owns lots of money or is allowed to manage it. And under what conditions is money is only given to someone? If the owner of the money or the owner of the one who gives out the money is promised more money back in return. Since only when you make profit you keep the power through having the most money as you can outbid those with less money with it.
So the businessman is only allowed to start his business, if he promises to give more money/power back than he gets and what happens if you give away more power than you get? Right, you get less power, simple math.
The owner of the money can also decide to refuse to invest in a certain project arbitrarily, if he does not like it, even if it promises to make profit, since he has the money and the power and can act independendly.
In that scenario there are ways to break out of that circle, if some rich person decides to act against these principles or someone finds a way through the system to start his business anyway. Thereforce there are multiple control layers stacked upon each other, for example you have a goverment stacked on top of that system that always demands profit and can just make laws against things that do not seem profitable. And above banks you have central banks etc. So the system is stacked and intertwined so you always have a point left to execute power, if parts of the system fail.
So you see that the one who controls the money can control everything that humans (who worship money) do, as he can simply place money at things he wants to have done and people will run after it, which in most cases is called goverment and of course they have to make sure the money comes back again after the goals are achieved, those mechamisms are called taxes and interest, because the owner has an interest in staying the owner. This is also an example of a master, since the master does not give any kind of service back, but still receives the money, just because he has an "interest" in it.