It's a dilemma for me. On an individual level I don't have a problem with people altering their bodies how they see fit (within legal limits ofc). But when it's as widespread as it is in South Korea it becomes almost perverse how commonly valued beauty traits are ones that most of the population won't be born with, and will feel pressured into getting invasive surgery to acquire. It doesn't seem healthy. For individuals (particularly young girls) and for their society.
Here's an example, a very popular procedure (and one that will make up most of that 70% figure you quoted) is double-eyelid surgery. It's a naturally occurring and common facial feature in the West and most people don't think twice about it, but it's very desirable in SK to have them, despite not being a natural feature of the faces of most oriental Asians. It's now so widespread that getting the double eyelid is almost thought of as going to a dentist. Anecdotally I know of Korean girls living in England who, on a summer trip back to South Korea, saw a medical practice was giving a discount on double eyelid surgery and got it done in a day on a whim, and returned home to the Uk with double eyelids.
Before -> after comparison pictures of invasive and expensive surgeries are plastered up on billboards there in public. Imagine on your daily commute having to stare at the face of a girl (or guy) who looks like you, who has had this surgery done to make themselves look more like the accepted image of beauty. Imagine what that would do to your self confidence. Especially when some of those features are just a natural result of your own racial heritage.
A huge number of idols have surgery done. In some businesses like that girls and guys will feel under pressure to have work done if they want to compete with other trainees. It becomes just another expense in life if you want to compete for a job, just like paying for an education. That's a bit sick. I especially feel sorry for the girls with wide jaws. A thin "V" jaw is very desirable, and these girls will get hugely painful surgery to shave their jaw down to size.
So..again. On an individual level I have no problem with it in principle. But when it becomes so widespread I start to think again. Conclusion: undecided. Happy that people can do what they want with their looks. Sad for the people that are pressured to take such drastic measures to feel they fit in, or to compete for work.
Specifically talking about South Korea, It's just a small part of a much broader problem they have of massive pressure on the average person there to be perfect in all areas. It's the suicide capital of the world for a reason.