People chose to live in the nation state for its protection and wealth. People flock to more wealthy nations for the opportunities they offer. Yes you surrender some freedom in any organisation but you also gain strength in numbers.
Libertarians are naive in the extreme in thinking that you could be secure living outside of any organised power structure capable of defending you against predatory external organised groups.
Yes nation states can be characterised as legitimised mafia protection rackets- but most people accept the benefits are greater than the costs.