There was a brief time 15 or so years ago where the $200-500k homes in the six or so blocks I live in were being snapped up by young upper-middle-class families on long 3-4% mortgages.
Those families' kids have now grown up, and the houses have appreciated, sometimes as much as 2-3x, due to a nearby light rail development connecting the neighborhood to the city at large on cheap transit. So those families are cashing out their housing by selling primarily to out-of-market elderly wealthy downsizers, typically from California, Arizona, Nevada, Colorado, and Texas.
The result is a neighborhood of 3- and 4-bedroom homes that once housed families of 4 or more people now mostly inhabitated by 2 or fewer people (many left vacant more than half the year as these wealthy retirees frequently travel). They also refit these former starter or second homes to accommodate these elderly inhabitants' reduced mobility and/or increase the home's luxury.
When these residents die in 10 or so years, even if the market corrects prices downward, these homes will now be even less suitable for anything but wealthy elderly inhabitants. The intelligent thing for the city to do would be to tear them down and replace them with accessible and affordable density; the reality is that the wealthy elderly who haven't died yet will spend the rest of their lives blocking such efforts out of spite.