No matter what system you think we have (or should), what system they tell us we have, or what system people actually try to enact, human-nature morphs it towards greed.
And if you're irrationally alienated by the word "greed", feel free to replace it with the comfortable alternatives we've rationalized; "saving money", "efficiency", "winning", "being successful". They and others are all rooted in "getting the most for me" aka greed.