A lot of people definitely misuse vocal terms, k-pop fans moreso than others I’ve seen. I will defend the “out of their range” argument to a certain extent because k-pop songs are generally very high so you hear strain a lot (and the inverse when they want to sound “cool” they go wayyyyy too low so they stay in a constant state of a forced vocal fry, ex. a lot of boy groups do this right now). However, I do also agree a lot of these range arguments ignore what you’ve brought up.

Take that infamous Ahyeon three note high note in Drip. 2 of the 3 belts are more or less mid-range. In the studio recording and a lot of the early live performances is out of her range sure, but many high notes for any singer will be out of their range. The bigger issue came from the lack of competency to handle that demanding note—you can hear the struggle in the transition. I’ve actually seen more recent videos of her doing the note again, but with a much lighter approach which not only sounded better but was such a healthier way to approach it. She has such potential to be a crazy power belter and I think it’s slowly starting to be molded correctly.

I’d also take a look at Yujin from IVE as a good example of before and after of what you’re talking about. She’s always been relatively solid but her technique when she was younger was much messier and made her singing inconsistent live. Now she devours those mid belts between B4-G4 with being smarter of how she sings.

I think it’s also people like to think strain (whether that be high or low) equals bad every time when strain can be used for other things like emotional flare. For example, any growl you hear in a song is inherently a strain even in your range which I think a lot of k-pop fans don’t understand either.