I think the most important element in music for me is emotions. Unless I'm going to get up and dance (in which case I would mostly only care about the beats) then I mostly consume music either when I'm working (or studying back in the day) or sometimes when I am lying down for the purpose of listening to music, so I care so much for the emotions being delivered and the way they make me feel. I think the most important elements as far as emotions go are lyrics and vocals. Lyrics are likely the most important thing for me in songs in my native language, but in kpop no matter how much many fans insist they stan for lyrics or that lyrics are the most important, I'm too opinionated to take someone else's interpretation of lyrics at face value and then proceed to feel things about it. It's nice to understand what a song is about but translations are nothing but someone else's interpretation that's influenced by their emotions, experiences and thoughts and that's vastly different from understanding lyrics first hand while listening to the song. So all there's left to deliver the emotions here is the vocals.
But to be Frank, this is not a black or white matter. Even I have many songs where I don't focus on the vocals much and primarily like them because they're fun or because I find the beats or arrangement interesting etc etc. It's just that if I am going to stan someone then they better have good vocals for me to be able to enjoy their music in the long run.
I agree emotions are pretty important element. Thats why I like Yoohyeon a lot because she is really emotional once she sing.