According to Wikipedia, "a sovereign state is a state that has the highest authority over a territory". The highest authority here doesn't mean absolute freedom, because we're are all acquainted with how banks and corporations control the so-called sovereign states. Remember,
He who controls the ledger, controls the world.
When your economy depends on debt, when your economy is controlled and manipulated by an unelected central banks, what kind of sovereignty is that?
Consider this:
A sovereign state is defined as a political entity that has complete autonomy and self-determination over its internal and external affairs. This concept is characterized by five essential elements: a defined territory, a permanent population, a government free from foreign control, independence from external powers, and the ability to engage in relations with other states. Here's the link.
Is there any country, nation or state, that's really sovereign?
If you know it's impossible to have a sovereign state, nation or country, it's high time we learned how to become a sovereign individuals.
Yes, I think the idea of sovereign state, is an illusion. We can experience the reality by becoming sovereign individuals.