Yes I agree with voluntarism very much. I see myself on onse side as voluntarist. On the other side as pragmatist.
I accept, that human are generally more conservative. And I am talking about progressives too.
So lets say we would figure out the most fair approach on how people interact with eachother. I see this truth as something that exists in an objective way. So the system, which allows the most people on the world to live in harmony without exploitation.
But we have to accept that even, when this model is found. There is no social laboratory to proof that our system is this perfect one. So in the end it is only important, if many people can understand this perfect system and therefore act in a way, that allows this system to form in reality.
So I mean it does not matter if you or someone tells that Tax are illegitimate or not, until you and enough others are as convinced to not pay these taxes. Not even at force. Before this it is an illusion that can never be proofen right or wrong.
An economic system can not be tested in theory. Eighter there is a place where people create this place without taxes. And if not it can not be proofen that it even works. Because reality does not depend on our understanding. It is the other way around. So to explain reality based on theory without real documented examples is nothing but a illusion.