2. The second reason a leader becomes a 'one man show' is because the people around him or her aren't competent and unworthy of empowering to act, make decisions and share the load. This, too is a sign or severe leadership weakness and solely the leader's fault since he or she is responsible for building the team, training them, creating an environment where they can succeed, setting expectations and motivating them to become more and do more.
It's time for weak leaders stop believing that the measure of their success is how much they do, how far they go and how much they get. A much truer measure of a leader is how many people he or she takes with them on the journey.
And if you have one of those bigger-than-Texas egos and think you're indispensable, just leave. My bet is when you drive by your former workplace in a month, six months or a year from now, it'll still be there. As Charles de Gaulle said, "The graveyard is filled with indispensable men."
Since you are dispensable, I suggest you build an inner circle of leaders, invest in them and hand off as much as you can to them because great leaders want to be succeeded, not needed. They know the only way to be indispensable is to become dispensable.