You have to look at it from the perspective of mathematics, like systems control theory and balance / equilibriums. Money flow is comparable to energy flow. Mathematical equivalence principles allows for multiple descriptions of the same phenomenon because every externally visible system behavior can be implemented in many different ways.
So even if that’s not how the underlying implementation looks like, you can switch the system to work like that without changing anything about how you interact with it. And that allows you to analyze the system in different ways that might not work in the current system