They also did a bunch of ‘condo conversions’ back in the real estate bubble which took inventory off the rental market and (from my non-scientific survey from driving a cab around the Phoenix metro area for nine years) they haven’t been putting any effort into affordable housing but just build massive, block sized, luxury apartments.
After the real estate bubble unless you want an hour commute all new housing is ‘infill’ and there’s a reason that a lot of that land wasn’t snapped up before. Now it’s super expensive, needs rezoning and quite often they’re tearing down multiple buildings to get a large enough lot size to make it worth their while.
Plus, they need a lot more water before they build a lot more housing. Phoenix is in the middle of the desert after all.