The country only stopped being a dictatorship in the late 80s, and that was only after it emerged they'd tortured a student to death. And it's not as if his successors were particularly clean either.

Hell, watch Squid Game or Parasite. Quite clearly there's something not quite alright in Korean society. Hell, watch Oldboy (2003). Genuinely one of the best (action) movies ever made. That'll also give you plenty of perspective on human nature and Korea.

The k-pop and k-dramas are quite clearly escapism, rather than a reflection of reality.

I've also heard plenty of horror stories about Korean schools from English(often American) language teachers, who were shocked at how bad schools were:

https://www.theguardian.com/world/2023/jun/07/we-torment-others-the-dark-side-of-south-korean-school-life-bullying-school-violence