What shows like Dark and a good Korean drama have in common is that unlike many Western shows, they don't run past their prime and outstay their welcome.
Korean dramas by default are 16-20 eps and end there, and if they're done well, stick the landing and provide a satisfying ending to a complete, pre-planned narrative arc, which Dark also managed to pull off.
> a good Korean drama have in common [...] they don't run past their prime and outstay their welcome
For me, it doesn't feel like it though. I got tired of k-dramas (and I usually watch the 16 episode ones, instead of 20), because it feels that around the 12~13 episode mark they throw in an unnecessary twist or something, just to get to the 16 episode mark. I do feel like they would be miles better if they usually aimed for 12~14
Dark, Babylon, How to sell drugs online, and 1899 (RIP) are all fantastic series.