Hi Yeez, the basic mainstream model of Economics historically shares a similar analytical structure to the Physics of old.
So it's plagued with models of equilibria, with the economy jumping from one equilibrium to another (in a sort of newtonian fashion).
You will actually come across steady state models in Economics etc... you can search for the "Solow-Swan model" on Wikipedia & you'll see what I mean.
However, Economists such as Steve Keen are destroying this assumption by showing that complex, adaptive systems which aren't characterised by equilibria should be our starting point. After all, what is Economics if it isn't a study of human behaviour?
Here's is Keen's lecture series:
https://www.youtube.com/playlist?list=PLqs7-zw9kiAKld49M_6xpPYL4TK_1XRzpHistorically, many Economists have challenged this mainstream assumption but many have voices have been ignored due to politics.
For instance, Minsky argued that the economy is complex and time dependent. Society is evolutionary and changes in response to endogenous factors, it isn’t an equilibrium seeking and sustaining machine.