There’s your simplicity: small groups of hunter-gatherers, no economic surplus, no wealth except for knowledge and experience; no political system - other than agreement by consensus; no permanent leaders; nomadic, so no permanent habitation. But that’s not the state of nature. That was human nature for two million years until plants and animals were first domesticated ten thousand years ago.
By collectively creating a moral system our ancestors got us out of the state of nature. This created an atmosphere of trust that facilitated many of the things that we value about ourselves: our cooperativeness, our willingness to help and to sacrifice for each other and our commitment to following rules, rules that level the playing field for everyone within the group.