What evidence in the book does Ishmael provide to show us that “Taker society” is not working

Ishmael and the narrator decide that man’s conquest of the world has actually devastated it, but that man progresses as though increasing "mastery" is the only solution to this devastation (80). Continuing this conquest will yield one of two results: the Earth will either be destroyed or become the paradise man believes it was meant to be. If the latter, man might progress to conquer the entire universe.

They contemplate the reasons man will not likely find paradise, including warfare, brutality, poverty, injustice, corruption and tyranny. The narrator concludes that man's inherent flaws - stupidity, greed, destructiveness, and shortsightedness - were bound to foil the paradise that the world was meant to be.