Not every kid can grow up to be Prime Minister (or President, or Benevolent Dictator For Life) primarily because there are too many people. If every Australian had to take a turn being Prime Minister of Australia some time after their 18th birthday, terms would be very short indeed (currently just over 2 minutes per person, by my calculations) and getting shorter all the time. It would eventually reach a point where terms would be shorter than the time it takes to say the next Prime Minister's name, even if it's two syllables like "John Smith".
The point is that it might be nice to have ambitions like that, but the world cannot accommodate all of us at the top. Some of us have to be the little people holding the others up.
Mokalus of Borg
PS - Most people do not choose that position willingly.
PPS - We don't have a concept of ambitious servanthood.