What I see (and am glad for) as the narraritive being challend is not just the simplistic "our ancestors were dumb", which some people may have, but this other one, that's so widespread that it's often considered "common sense" and seems more "objective":
ALL hunter-gatherer societies/culture are fundamentally the same, because the main components are somehow a necessary consequence of being a hunter-gatherer (which is a stable category, which applies to a variety of human cultures throughout history, that can all be summed up as being more or less the same), and therefore we can tell how ancient "hunter-gatherers" lived by looking at contemporary people we call "hunter-gatherers".
No, no, no, no, and no.
And, in fact, human culture always has and still is various, diverse, and with many possibilities. From the review:
> Above all, it is a brief for possibility, which was, for Graeber, perhaps the highest value of all. The book is something of a glorious mess, full of fascinating digressions, open questions, and missing pieces. It aims to replace the dominant grand narrative of history not with another of its own devising, but with the outline of a picture, only just becoming visible, of a human past replete with political experiment and creativity.
> “How did we get stuck?” the authors ask—stuck, that is, in a world of “war, greed, exploitation [and] systematic indifference to others’ suffering”?