nihilism, darkness
It doesn't matter whether or not that is actually true, because we would not believe it. We are constitutionally incapable of accepting that there might be limits on our accomplishments. Our brains don't work that way.
Even if all of the evidence told us that restraint is the only way to survive, we wouldn't do it. There will always be someone that can invent a story about how we can think our way out of the issues we face.
But what if there isn't a way out?