Why the gravitational force decreases towards equator and increases at poles?

Firstly, the amount of centripetal force. On the equator, we would experience more centripetal force, because we would experience more of Earth’s rotation. However, the poles don’t, because they are located right at the top and bottom of Earth.As here the radius of earth is less than at the equator so here R decreases and as a result of it gravitational force increases .

The centripetal force also influences the land around it, which leads us to the second reason. The land on or near the equator would also experience centripetal force, and thus slightly bulge out more than the poles, which are experiencing very little centripetal force. Because the land is slightly bulged out, we would experience less gravitational force; the equator is further from the core.