Humans traded away a lot of strength for other things like precision of movements, cognitive abilities, decreased energy usage and the a huge endurance at walking.
If we evolved to be gorillas we would be gorillas. Instead we are much weaker, but very social animals with peak cognitive abilities.
Instead, we find a balance. As I've heard it explained, and to oversimplify, jacked men get laid, but "softer" men get married and live happily ever after. The number of jacked men who sleep around seems to significantly drop after age 30 as well (I have no concrete numbers to prove this btw).