It's natural, and inevitable. Some people don't need or want as much power as others. Everybody has their preferences as to what kind of power they want most, and what kind, and amount, they are willing to yield. Not every person should have the power to, for example, declare war.
The fact that power is unevenly distributed is neither fair, nor unfair. Fairness is a human concept. Only humans can be fair or unfair. Some human actions that affect the distribution of power are fair; some are unfair. Giving people powers that they deserve is fair; denying them powers that they deserve is unfair. It is impossible to make everyone identical in their powers. Trying to do so would be foolish and unfair.