The pole in the ground is not actually the most important part of the grounding system. The bond to "neutral" and the fact that "ground" is connected to all exposed metal is the most important part. The goal is to have all exposed conducting surfaces at the same electrical potential. Sticking a pole in the ground and connecting a ground wire to it just makes sure that that potential is the same as earth itself. But if someone came to my house and cut the wire to the pole in the ground, I might never know.
This is really a big and complex topic. Why are you asking? Maybe if you explain more of your thinking someone can provide you a better answer.