I do not believe humans are inherently greedy, because there is a lot of evidence that other tribes/cultures are far more cooperative. I can't remember where I saw it, but someone did an experiment with a bunch of indigenous kids. They all sat in a circle and someone put candy in the middle and said whoever got to it first could have it. I can't remember exactly what happened--either the kids all sat there and didn't move, or they moved toward the center in unison, but it showed that no one of them wanted to be a "winner" at the expense of their friends.
One of Erich Fromm's books talks about the toll the Protestant Reformation had on the culture in terms of the relationship between work and grace. Can't remember that book, either. (I need to take better notes!). But it propelled human culture into the mode of "productivity" at all costs. And that generated a culture of competition, capitalism and Ayn Rand-style objectivism
There are people out there-some inspired by E.F. Schumacher--who believe that a negative growth would be most beneficial for us now. I'm not going to hold my breath in hopes that that will happen any time soon unless it's by accident or some cataclysmic event.