The most ruthless people didn't usurp the power structures, they created them. Before they existed we had lawless anarchy.
We can live in harmony with the earth until a comet hits or a super volcano erupts at which point humanity goes extinct. To survive as a species we must continue to push technology forward as fast as we can. That's where capitalism, ambition and competition come into play. They are positive forces that are human's only path to long term survival.