This was as true in the ancient world as it is today. There is no point in two people trading their hamburgers and fries with each other if they are both clinging to a liferaft that can carry only one. I take it that Phil sees ancient societies as being in something like this situation, where the cost of refraining from exploitation is so great that it outweighs the gains from cooperation. Still, suppose that's right. We can still ask whether it follows that exploitation, and in particular the exploitative structure of the state, would have to be seen as superior to cooperation.
Most states involve the exploitation of a majority by a minority.
Thus the maintenance of the state, while materially beneficial to the ruling minority, is harmful to the oppressed majority. Yet such states typically depend for their survival on the compliance of the oppressed majority. So even in a zero-sum economy, most people do not benefit from having a state and are in a position to topple the state if they so choose. Arguably, then, the survival of the state has depended more on ideology and false consciousness than on genuine economic necessity. Of course, there is the danger that those who have toppled the state will try to replace it with a new state in which they, the topplers, are the oppressors.