As a Korean American who’s been in the US for nearly all my life, I didn’t understand it at first. Then I went with her and saw the Korean medical system in action and I’m now a believer.
You can visit one clinic and get a comprehensive full body diagnostic exam. Results come out within a week.
You can make an appointment with a doctor and get all associated procedures done (blood work, X-ray, MRI) often on the same day, same building, same staff.
What takes weeks if not months to complete in the US takes days or a week or two there.
It’s like a less personal, but sometimes faster and more efficient, version of the “concierge medicine” services popping up in the US.