There are two reasons why a golf ball does not bounce as high as the initial drop point height. First, when the golf ball hits the ground, it experiences a force of impact that causes it to deform slightly. This deformation dissipates some of the energy from the initial drop, reducing the height of the bounce.
Second, when the golf ball bounces, it experiences friction with the ground, which also dissipates some of the energy from the initial drop. This further reduces the height of the bounce. Together, these two factors explain why a golf ball does not bounce as high as its initial drop point height.