This is a simple one, there is no one else in the world pushing harder and finding better performance results in pushing the limits of our human abilities. No one else is challenging the status quo as much or has offered more to humanity's longevity.
If the utilitarian, long-term survival of the human species is what one believes in...there is no one better than Elon Musk at this point moving the world forward.
Many people may argue my last point, but he gives hope and shows people that they can achieve what they dream of and that is more important than just about anything a single person is working on. Sure he has an entire team, but he is the leader and without him, these companies simply would not exist and would not be nearly as successful as they are.
It is a classic story of what a real leader looks like. In those respects, I cannot think of a better leader on the entire planet.