I think in the US, we’ve come to think of dressing casual as a way to remove the barriers between hierarchies. We think of it as a nice thing to do.
In Korea, looking dressed up and professional is a way to show that you care about and respect whomever you meet and are working with.
If you dress sloppily, it means you don’t care about the other person. This is especially pertinent for the first meeting, first impression.
As you might guess, I’ve been dressing up a lot more than I would at home. Given this lens, it’s easier to take!