If one honestly perceives that a serious social challenge is "greed", then you're presented with two choices
1) Complain about how others - notably "rich people" - allocate their resources and money
2) Begin immediately to a committed lifestyle of giving away 10% or more of your own income and resources (time) and don't look back.
I decided about six years ago to do "2" and have since found that I have very little time left to waste on "1".