It is worth noting that the vast majority of people think this is necessary in South Korea. People would actually blame those who try to enter, as they are liabilities to the country. You are expected to not be a burden to others.

Is the Untied States considered a dangerous country? Cause it should be

This is fascinating. And I don’t know what is the right way to go about it.
Should a country actually restrict and punish their citizens?
It feels double edged sword - rescue missions, geopolitics, hostage situations - can be mostly avoided.

It is kinda being a parent that forbids kids from doing stupid stuff … But when those kids are adults, that’s a different question.