when something affects a person's mental state to the point of hiding, feeling very low, depressed etc, i think it is enough cause to get plastic surgery
personally, i absolutely HATE my nose, not least in the fact i lost a tonne of weight, from going normal to ridiculously thin, lilly will attest to my skeletonness>.< which affected my face in general - but it is not enough for me to get plastic surgery
if a person goes for bigger boobs coz theyre not happy with aa ones, then so be it, if it makes them feel proud to be them. good on them, as long as they do it safely and correctly
if a person already has, lets say gg boobs, and wants to go for a j...for maybe the hell of it...or a boob contest, idk, i dont know what possesses such a person to do said thing, i would not approve so much, as it would seem unnecessary imo, but it is their body and their choice inevitably.
things always need to be thought out, or they will be regretted later, and thats when the horrors come to light :p