Problem in most housing constrained cities is 'downtown' is very small. As an example, only about 7% of residential Seattle land is zoned for multifamily, and that is an even smaller portion of the metropolitan area. That's not sufficient for a city that has grown by a third since 2000; and Seattle is considered a friendly city for such multifamily developments.

I agree that what is zoned for a city like Seattle isn't going to be representative of most American cities, and in particular the ones that the person I was replying to was talking about (mid-sized American cities away from the coasts).

Personally I'm less interested in Seattle, New York City, San Francisco, Washington DC, Chicago, etc. because the constraints there don't apply to Columbus, Pittsburgh, Grand Rapids, Oklahoma City, etc.

If you'd like to see for yourself, take a look at a satellite map of a city like Columbus and look at the downtown area. You'll find lots of vacant buildings (well you'd have to just know that so that doesn't really count), and surface parking lots that aren't used that often. If you compare that to Seattle you'll see a big difference.