I think it's because she always play strong women with charisma kind of roles but many other actresses have very strong screen presence even if their character is simple, goofy or even side character.
I didn't see anyone complaining about this drama being explicit or being 19+ rated because it is not even released yet and even the rating isn't updated yet but knowing the history of tvN I don't this it will have any such scenes even if it is 19+ rated but who knows yet. But there are already so many people here complaining that people are complaining about this drama being explicit. Bro who? Which drama are you talking about? Why do you feel the need to start that topic? Who is the childish one here?
It's always funny when people claim sex scene is "western thing", when Korea has some of the most exclipt scenes…
KMovies always had explicit scenes but kdramas never had any and just for this reason so many people got tired or western series and started kdramas. And sex being a part of life doesn't mean everyone would find it normal to watch on screen, you can know about people by their major events in life not by watching them in bed.
Her journey seems really seems really amazing, until 2020 she was just doing supporting and guest roles when her age was 50 and after that she is main lead in every big project.
K-Drama 
But there are already so many people here complaining that people are complaining about this drama being explicit. Bro who? Which drama are you talking about? Why do you feel the need to start that topic? Who is the childish one here?