It’s just different culture. Celebrities in the west get away with tons of stuff, that may not affect their career. While in SK is very strict.
Plus kpop groups live in dorms, with handlers (managers), often have to ask for permission to leave (or sneak out) etc etc.
When your a child star with money, no one can say no to you. Not your parents, not your company, so they tend to go down bad paths. Plus drugs etc, just aren’t as frowned upon in west vs SK.