Basically same problems as Japan. Low birth rate, unrealistic work life balance that's helped GDP but now both are facing demographic shock that'll destroy the economy in a generation.

Considering Moon Channel's video on South Korea (tldw; he explains around 24:40 in the video how strongly neoconfucianism became the state ideology and that still endures to this day - and how highly important hierarchy is), I would say that yes, an underling would NEVER dare go against someone above them.