Humans want more even if he has many things already. The hunger of having much more will not stop them from making more sources of income. They want to become the richest person in the world so they will create more and more sources that can produce them wealth. I don't know if that is competition among the richest people but all people, not just rich people but also poor people want to be wealthy. The other things that can push these people are greed. They want to get more and more without thinking that it is enough for them. They want to eat a bigger portion than others.