In spite of the fact that one person making all decisions in government never turns out very well, in theory there are certainly advantages. The first advantage is efficiency. There is no need to consult endlessly with others or propose legislation that others must pass.  The second advantage is speed. One person making decisions can act swiftly, and in times of emergency, for example, an attack, this can be a powerful advantage. A third advantage is consistency. When one person is making all the decisions, all decisions are emanating from the same world view, the same knowledge base, and the same emotional makeup. Having different people in government making decisions implies different opinions and different bases upon which to act. This means that a fourth advantage is that there is no conflict.  One person is in charge, and no one has the power to oppose him or her.  Finally, a fifth advantage can be stability. A nation knows that as long as the person is in charge, there will be no extreme changes.  This, of course, is premised upon a leader who is a sane and stable human being. There have been leaders who have not been, for example Idi Amin, lending his country no stability whatsoever.  It is important to understand, though, that in spite of these apparent advantages when one person makes all decisions in a nation, even if that person is duly elected, this inevitably devolves into a dictatorship, since as they say, "Absolute power corrupts absolutely."