Which idols are substance over style?

Kpop has a reputation for being style over substance. Give some examples of idols who are substance over style-basically skills over aesthetics. For example a male idol who is short and doesn't have an aesthetically appealing tone but can do some of the following: write music, produce music, vocally stable-to the point where they are always on key and rarely crack, can dance well to any song when asked to improvise, can sing any popular song on key and on beat at moment's notice. Improvisation during variety or acting is questionable. I don't know if that's style or substance.