The natural result of having borders? If you think people should be able to live wherever they want then where do you draw the line? Can I come live in your house and sleep in your bed whenever I want?
Did you just compare countries with houses ? Do people still use this tired argument ? The line is pretty obvious, it's called property of usage, you can't be denied what you actually need to live a decent life as defined by your society, but arbitrary borders based on the arbitrary, random fact that someone was born at a random place in earth is one of the worst criteria we can use