It seems anarchy is the de facto human political system, if this data holds true. Our centralized societies are only a blip in our history as a species. Their probability of sustention seems to be undefinable to either degree, whether it stays this way or stagnates to another protocol. At the absolute least, to say big government is here to stay is far from being an absolute fact.
The data shows that anarchy is what prevailed for illiterate societies where most people died below the age of 50. Since we don't aspire to an illiterate society where people die younger than they do in our comfortable liberal states, anarchy doesn't really have much to offer.
The average hunter-gatherer lived to 72 with little to no disease. Most deaths occurred only due to trauma and physical energy. In regards to your argument of people dying young due to starvation and disease -- that is a recent travesty. Most of this suffering is due to our own artificial constraints and the centralization of wealth.
Literacy -- literacy is just a hobby; a means to preferable ends. It shouldn't be used as a unilateral ruler for the success of societies.