Yeah, that's kind of bullshit. They send their kids to public schools and maybe public universities later, drive on public roads, use water, electricity, etc. They also have a place where they buy seed, animals, neighbors they attend church with, etc. Not to mention the markets they need to sell to.

There is some level of self-sustainment but it's a myth how 'independent' people really are.

They might be detached from the federal side of things but they still also have to interact at a state level.