I disagree with assumptions that any services require a central monopoly, and suggest the idea of consumer choice should extend beyond how 50% of what is stolen from them should be spent, and instead 100% should be their choice. If we are to have a compromise, my minimum is the absolute elimination of individual income and property taxes. Corporations are another matter, since they exist under state license and state grants of privilege.
Oh, I thought it was clear that it would end up at 100% - I must have missed it. My point is, that it has to start, but it isn't going to start at 100%, unless something horrendously catastrophic happens, which would mean we would have larger problems to deal with.
And, I think that there would still be various forms of opt-in centralization for a lot of things, though the scope and scale of them would be narrower than they are now.