Nothing is voluntary with a gun to your head. There are factors at play, the omnipresent state, that youre ignoring. Capitalism in a stateless world is like Serfdom in a landless world.
By the way, Im pro monarchy.
This suggests that you would not oppose those AnCap fellows, if only you believed it were possible.
But you believe instead that Capitalism requires a state so there can never be such a thing as an Anarcho Capitalist geography?
I oppose it because I believe it is impossible.
Capitalism analyzed ignoring state power (which requires analytic gymnastics) still results in oppression and coercion.
I can't claim to speak for the AnCaps, but I think they do not ignore state power in any way.
Rather they seek to make state power redundant or obsolete, and to separate the influence of capital upon state power.
By your description of the oppression and coercion inherent in naked stateless capitalism, it seems you often mean what most might call enticement. The rights of violence is the monopoly of the state.
They don't ignore it, even though they might try.
To analyze "pure" capitalism, one has to ignore the state's influence.
The problem is that what one winds up analyzing, by ignoring the state, is an independently oppressive, albeit incomplete picture of what capitalism is.