New afordable housing isn't built. Everything is "luxury" so that developers can maximize profit. When someone tries to build affordable duplexes the NIMBYs say not in my town.
(Alternately, if no luxury unit is built, many of those buyers will be forced to buy the best-of-the-rest if they want to move in, putting more pressure on the middle, which in turn puts pressure on the affordable.)
The only place cheaper housing is being built are in developments on the far outer suburbs of flyover cities. But even those builders are having trouble with supplies and labor.
The pools are unused most of the time, but having a pool in the building increases the value estimated by property appraisals' checklists.