taxes are needed unless we want a complete anarchy.
This is incorrect. Government could be funded voluntarily. It's not binary between taxes and anarchy.
This will admittedly be an argument of symantics but i dont think this is correct. Tax collection is one of the defining characteristics of government. Any organization that is funded voluntarily is necessarily not a government by virtue of the fact that it is funded voluntarily.
I think the right term for an organization that behaves like a government in other ways but doesnt force people to fund it would be mutual aid society.