Everyone has an ego. And certainly there are many CEOs that you can point to that have big egos (usually identified in the negative sense).

Is it helpful to have one? Interesting question. It depends on what you mean by ego.

CEO ego is positive if it gives the person the ability to continue moving ahead when things go bad, enables them to withstand rejection (i.e. when fund raising or trying to close a sale), or gives them the confidence to make decisions in the face of ambiguity. It is helpful if it helps the person override the emotional fear that is at odds with doing the right thing.

CEO ego is negative when it denigrates other people, closes the person off to listening to others, stifles initiative or dissent from the people who work for them, or blinds them to the reality of a situation different from the way they may wish it to be.

The ego is required to function. I am defining the ego as "self perception". How you perceive yourself is usually how you present to others. The stronger the ego believes it is, the greater chance of leading those who believe they have weaker ones. By this statement I suggest that ego is good if your want is to lead people.

If you want to gain greater perception of what your ego does, I suggest reading "A Course in Miracles". I don't know if it will help you build or rid yourself of your ego, but you definitely will be clearer on the function of your ego.