Gonna be that guy and say, when you leave the US and spend enough time in enough global cities you realize, yes, most US cities suck. By comparison.
A city doesn’t have to be a traffic jammed, pedestrian fierce, crime singed, garbage strewn, expensive, angry place dotted with homeless, addicted, and the mentally unsound grasping for some attention, that only works for the 1% of residents with enough money to cocoon themselves away from the maddening crowds. A city can in fact have nice things. Affordable to most residents.
Seoul is like that, and while it has its problems, it has a lot of nice things. Things that work for the average resident, not just the super wealthy. Things like a very functional bus and metro system, that goes almost everywhere, quickly and inexpensively, with one swipe of an easy to get card. Clean public restrooms, including in every subway stop. Parks that snake the length of the river. Residents who are happy, content, and focused on being good citizens.
Why is that? There is, for whatever reason a shared public trust (or more cynically, enough cctv's) that public spaces can exist, without immediately being soiled, destroyed, or exploited.