The existence of traditional nations is the antithesis of voluntaryism, as traditional governments are inherently involuntary. Any system of governance that is entirely voluntary can't really be called a government.
I'm sure you've heard of "anarcho-capitalists" before. Ancaps and Voluntaryists are one and the same; Voluntaryist is just a less edgy word and has gained a lot more traction. National borders cannot exist without nations, and nations cannot exist voluntarily. Private property borders, however, would exist and would be able to be defended.
@adamkokesh has a lot of videos on DTube and YouTube covering the ideas of Voluntaryism and is running for the Libertarian Nomination for President in 2020 on the sole platform of dissolving the Federal Government. If you'd like to learn more about voluntaryism, his videos are a great start.
He's trolling people. Even if he got elected, which is a joke by itself, the Office of the President has no authority to dissolve the federal government.