Over 6 million years of evolution, since splitting from the chimpanzees, the human's learned to be great gathers and hunters. They had to get up each day and go for it or they would perish.
So it's in the human genes to gather and acquire things. And in those days people shared because all members of the tribe were important and knew each other.
But when great wealth came, the managers of the wealth lost touch with the gathers (the workers) and became arrogant. They didn't have to rely on the clan or the family, they had whole villages. and then whole empires to support them. So greed was born. Now greed is considered a virtue, unless you're so poor that you have to rely on others just to get by. This has left so many people walking around thinking like kings.