This is because the mountains are formed by the collision between the tectonic plates.
Explanation:
The mountains are formed by the shock that occurs when the tectonic plates collide with each other. By the force of this shock, the surface of these plates folds, generating a mountain on the Earth's surface.
As these shocks between the tectonic plates have more strength and intensity in the regions of the edges, it is easier that we can see the existence of mountains in the regions that are on the edges of the tectonic plates than in the regions that are in the middle.
“His third law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal and opposite force on object A. Notice that the forces are exerted on different objects.”
