Plastic surgery is a weird thing in kpop. On one hand, you have people saying "there is nothing wrong with PS" but when you point out their bias has a nose job they will get defensive. I think PS is extremely common in kpop, if not PS then other beauty procedures. Not just in kpop but in all entertainment industries.
Kpops beauty standard is unachievable, so even idols who are stunning have probably done some subtle work. And that's fine, there is nothing wrong with PS.
What I do have a problem with is how celebrities (not just Kpop) sell us products foolling us into thinking "if I buy this I will look like them", when in reality they have had PS done. And then you have kids looking up to these celebrities and feeling bad they don't look like them.
Again not just kpop, I remember when Eternals came out Kumail Nanjiani got ripped, he had abs and everything but he kept pretending he got it through "working out". There is no way on this earth he got that body because he "worked out". But people believe it, then they feel bad cuz they don't look the same.
Even I have moments where I feel like my waist is too big etc. But I try really hard not to compare myself with idols/celebs, cuz everything we see is the result of work, if not PS then other beauty treatments, private trainers, diet coaches, etc.