I live in a suburb in the UK. We have groceries in walking distance. I can get a train or a bus anywhere I want. This is all achievable without building a metropolis like Seoul.
I don't understand why people hear suburb and think unwalkable and no public transport. It's normal in other places.
If you're not familiar with U.S. suburbs, their history, and how they were explicitly designed... that's fine, but it's kind of condescending to talk like those of us who are aware of U.S. suburbs have some "curious" and bizarre idea about them.
It can be done in America. I've seen small, walkable towns there. In fact isn't America famous for its walkable small towns? Small-town America. You can even find them near where people think they're impossible - like the small coastal towns in the Bay Area such as Half Moon Bay. Completely walkable.
And to repeat the parent comment back to them:
> It makes me rather depressed knowing what people are missing out on, what life is capable of being like.
You can say the same about their own view of suburbs!