>>509298902 (OP)several reasons.
1. Generational wealth. when you live in a house that costs millions in the west with all the luxuries you can imagine, why the fuck would i live in a 30m2 apartment without even 10% of the luxuries i am used to? then there is family power, if everyone works, the costs arent that monstrous. also your parents can take care of kids,meaning you can have kids, unlike your disgusting state that is well on its way to extinction. and like south korea. whats the point of you having money if you are extinct in a century?
2. Salaries do not permit renting places ,and if they do, why the hell would you pay more than half of your salary for a place thats not even half as good as the house you were born in?
3. Your village, city, house, wherever you live is surrounded by people you know very deeply and can help you.so why the fuck would you go somewhere nobody knows you where you are on your own? you think some unknown cunt will help you after a month when you realize your salary isnt cutting it? i like to think such good people exist, but i wouldnt count on it.
4. because i love my parents, and i cant fathom just outright abandoning them like americans, seeing them once every few months, or putting them ,God forbid in some home where they will be abused.
tl/dr the cultural gap between a loving family in the south, and the cold uncaring boomer assholes in the west and north is far to big for you to understand why people dont wanna move out.