That about sums it up. The drive to always want more is just how humans are. If it wasn't, the human condition would never improve. However, you need to recognize it for what it is and don't let it control your own happiness.
The older I get the more I realize that doing what I want to do now is much more rewarding that doing what I think will make me happy years from now.
From a christian perspective, the natural discontent stems from the fallen nature of man. You're worldly accomplishments will never be able to satisfy that discontentment, as the two areas are unrelated.
Nobody is saying that evolution is selecting for some nebulous sense of "improvement." Reproductive success leads to traits being passed on to successive generations, and general survival is merely one precondition to reproduction. The human impulse to jockey for status is a reproductive strategy.
I've chose startup grind instead of super rich Facebook jobs 3 years ago and am still living like a student and see no need to own a lot of things. Am I that "special", to me it seems completely logical to sacrifice short term rewards to be in for the long run, delayed gratification and everything.
Once I've made it, I don't see either, why I would burn myself just to have e.g. $20M instead of $10M. wtf?
When discussing evolution and species, it's best to avoid the past tense. Evolution never ends, and nature is shaping us as we speak. 200,000 years ago, we wouldn't have recognized our forebears, and 200,000 years from now, we won't recognize our descendants.