Survivorship bias. All the corpses aren't here to tell us anything. Just 100 years ago, most parents would bury at least one of their infant children. People back then were tough, because the physically and emotionally weak died off. Humanity's "natural state" is like the animals, to kill or be killed, to wage war, to reproduce, to die. The difference is we have a big brain that strongly incentivizes us to try to leave that world behind. Its not perfect, but we've improved in basically every measurable way on the scale of our species.