There's a common complaint I see across many local housing discussions, which goes something like: "We need affordable housing, but we shouldn't build to become <nearest metro>!" and of course the shorter "We're full!". But that then ignores the fact that the United States doesn't have internal movement controls. If somebody wants to move to a city, they can. The richest / most motivated group of those people will purchase housing until the housing is gone. In extremes this means knocking down old housing stock and rebuilding new (but not new density), or massive gut & remodels.
Assuming the city is desirable enough (ie. a mountain town). You get this, and you must choose two:
* Allow people to move into your city (Must choose this one).
* More units / Affordable Units
* Keep city 'character' by avoiding density.
Some places choose character. Much of the Bay Area for instance, with 1.5 million dollar single family homes, and not one apartment as far as the eye can see. And others choose to build lots of units, although it's hard to find examples in the US. Tokyo is the one that comes to mind. Many people in Japan wants to move to Tokyo, and they build tons and tons of apartments to support that. The character of course was already big city, but it's grown into mega-mega city.