From an evolutionary perspective, you are technically right. We've evolved to reproduce and to support traits that aid in reproduction. From that perspective, i

From an evolutionary perspective, you are technically right. We've evolved to reproduce and to support traits that aid in reproduction. From that perspective, it doesn't matter if we as individuals are okay or not. However, we evolved from social, tribal apes. As an individual, I want to optimize my own happiness and contentness because it feels good. Humans have mirror neurons that cause me to feel the emotions I see in others. Because of that, I have an incentive not only to fight for my own comfort and happiness, but the happiness of others. What's interesting is that our mirror neurons can extend past humans. I have the capacity to feel for other animals. That gives me an incentive to either care for their happiness or never think of them whatsoever.