You sound like a psychopath.
You really have no trouble in killing a whole bunch of people. If this happens, everybody else that remains will be scarred for life and traumatized for generations.
Adolf Hitler didnt want to kill everybody, he just wanted to select certain people, and look what that did to human history. A lot of people thought Eugenics was the future.
OP, this is an awful idea. If you want to improve humanity, you have to drive humans into a place of personal evolution, and spiritual progress. Let me tell you that the system, the global system itself, is rotten. And people in control believe it should be rotten. All it would take is better intentions from the top-down. Less of an effort to keep humanity drowned in water when they would naturally float. You don't have to kill people. At all.. that would only make what we have now incredibly worse..