The argument that government is “necessary” stems from a presupposition that there is something special or different about agents of the government.
If there is not something different, then there is no reason to expect better outcomes from those people (government agents) than from these (private citizens).
The defender of government will appeal to monsters that lurk among the private citizenry. Somehow they are excluded from government? History is dripping with the abuse of power of government.
The argument for no stealing and aggression at all (which would prevent the government from coercively and parasitically living off of the production of private citizens) is simply that with government there is one group with monopoly on theft and aggression. Without government there is no monopoly on theft and aggression.
Any fear you have of your private citizen’s misuse of power (the robber baron…booh!) is amplified by government monopoly on theft and aggression.
There simply is nothing special about government agents except monopoly on violence. Otherwise they are just like you and me.