Hello there, back in 2016 i've watched this documentary named 101 East from Al Jazeera and it showed many younger Koreans are leaving the country for no reason:

Is there are some reason for this. I know that they are leaving older generations behind and just leaving them to die with no supporting them.

I thought it's because it's hard to get a job these days, even with their high level of education. And the work culture in South Korea--the obligation to work late and join afterwork drinking session and all that--means that it's hard to balance your work with your personal life, or even to have a personal life at all, and some people simply want a more balanced life, which they think they could get abroad.

They’re not leaving for good. They go here abroad to study English or delay army recruitment but they go back to korea anyway. Lots of koreans put up businesses  where in other countries (like in my countey there are a lot of korean groceries and restaurants popping up) but the money they earn they bring back to korea. It’s mainly for business/education reasons why they go.