This is basically false. There are plenty of regions so untraveled that, even if a nation DOES claim ownership, it's impossible for them to enforce it.
Your issue is you don't want to LIVE there, because it's inhospitable and there's no access to services and so forth.
In short, you want to mooch off the benefits of being a citizen of a modern society, without taking on any of the duties of citizenship. That isn't how anything works.