Does it? It is true Pinker spent a lot of time on trying to compare death-rates with hunter-gatherers, but it's not obvious that the comparison is that favorable for early empires (as opposed to modern civilizations) and I believe he also discusses ways in which people were worse off due to formation of states, such as poorer nutrition, taxation, and massively organized warfare. (It's a very big book and he covers a lot of nuances.)