This is an interesting question that demands a book or two to answer!
Sometimes more is less and sometimes less is more. If we strive and push for purely material things there may come a point where we reach a stage of saturation and have to say, Hey, Stop. This is one thing too many. I'm not as happy as I was, I've lost the ability to judge and value the true things in my life.
This could be true for alot of western people, used to affluence and lots of toys! Perhaps if I was a subsistence farmer in India or south America I'd have a totally different outlook but I'd still be pushing for more. It's human nature to get the most out of any situation - generally speaking - for oneself, for the family. Inequality does have to be addresed though because that to my mind is obscene.
We push in many directions. In all aspects of life- at work, in play, in sport. It is instinctive yet we have developed religion and philosophy to help us curb our continual need to push and gain ground. Life is complex and we're having to adapt to so many rapid changes. Yet despite all the greed, the wealth, the ego pushing, the aggressiveness, there's compassion and care. Despite the selfishness there's sharing and a will to give where it's needed. This is heartening.