A more in depth response than I expected, thank you!

I'm in agreement with you for the most part, lots of government systems are wonderful on paper and terrible in practice. I'm not advocating communist style work placement or anything like that. I think a government's three main roles are to ensure people behave fairly and equitably towards each other, to collect taxes in service of the common good of the nation, and to leave you the fuck alone otherwise. I think people that like to claim taxation is theft are generally extremely naive. Most people who find some measure of success are able to do so only because of the infrastructure and support the public provides.

Towards your question of voluntary or not, it's the same question of why should I pay union dues even if I don't want to be in the union? It feels like a measure of control placed upon you, however whether you want to participate or not you benefit from the actions of the union. We are supposed to exclude people from public roads if they don't want to pay taxes? What about from schools or fire department coverage? How would that even work? Even if you owned a helicopter to bypass all of that, more than likely your work depends on the public infrastructure to function.

To that end I support a more free and open immigration policy between developed nations. Really the only way to make this voluntary is to have the option to move to a different country and more aligns to your philosophy. I would love to move to Germany if it was feasible, however I highly doubt both my fiance and I would qualify to immigrate there based on their requirements.