That is indeed what 'zero sum thinkers' tend to assume about government. Government is, though, a solution to 'collective action' problems, which usually have

That is indeed what 'zero sum thinkers' tend to assume about government. Government is, though, a solution to 'collective action' problems, which usually have prisoner's dilemma payoff matrices. A problem could be solved if everyone acted. But individually, none of them have the incentive to act alone, so the default result is for nobody to act. Government allows a group of people to agree that when there's a collective action benefit available, they'll take it, together. That is explicitly not a zero sum outcome.