Lowering the mound is more an effect of changing the amount of leverage the pitcher can gather from the ground, increase the velocity of their leg push down a hill. Think of running down a steep hill vs running down a slight decline. A steep hill will increase your top running speed regardless of height.
Taller pitchers do get a slight increase in their ability to use acceleration due to gravity on the ball from a higher release point and have a longer reach towards home plate.
I wonder if the durability aspect is true though, as the longer lever arms should throw the ball faster, but at greater torque force on the endpoints (elbow, shoulder).