Why is altruistic behavior something that would not flourish in a world where natural selection occurs?

Why is altruistic behavior something that would not flourish in a world where natural selection occurs?

Natural selection is tied, in part, to reproductive success. Spending your energy on altruistic behaviours lowers the energy you have to spend on finding a mate and breeding, so you will be outcompeted by your less altruistic neighbors.

Altruism results in every individual being treated fairly and the same so it would not produce the diversity that in needed for natural selection

Natural selection has foresight and plans for the future, and since altruistic behaviour like building a road takes a long time, it’s not worth it in the long run.