Question

why does current flow from high potential to low potential?

Answer 1

Electric current flows from a higher potential to lower potential.  When a circuit is connected using conductors, an electric field is established in the direction towards lower a potential point from a higher potential point. The electric field exerts an electric field on the electrons in the conductor in the opposite direction. So electrons drift in the opposite direction from - to + terminal.  We call direction of current to be opposite to the direction of motion of electrons.

Also, like water or stones etc. move from a higher energy point to a lower energy point, current flows from a higher energy point or higher potential (+terminal) to a lower energy point or potential (- terminal).

Answer 2

We know that current flows from positive ions to negative ions. So high potential have positive  ions and low potential have negative ions.
And also the flow of electrons is from negative to positive and the current flows in opposite direction to it. So current flow from high potential to low potential.