And the moment anyone got wind of an attempt to try to do such a thing, enough humans would go to ground you’d never actually succeed. Hell, enough are probably already under ground for whatever reason you’d never succeed even if you did manage to catch the whole world by surprise and somehow actually release it all at scale.
The Nazi’s did not fail because they failed to try to kill humans at scale. Frankly, they did it at the largest scale since probably Ghenghis Khan. Certainly in a far more industrial fashion.
The issue is that it’s actually really hard to kill a lot of humans. Something that personally warms the cockles of my very human heart.
Embrace your ancestry of murderous (and loving) hominids, and aim to use it to make things better. Rejecting it is a false path.