If all you have is stone tools, you can do this to your heart's content, and you don't generally take too much. People put all their energy into tearing up and eating and reproducing, and they just held their own. We were just another predator. But we got good at killing and eating and growing more people. Yet the instincts remain the same.
People feel that to stop is to die.
Which would have been true in the stone age. Reason says slow down. Instinct says go faster. For the last several thousand years, instinct has won the decision. The only thing to stop it is to run out.