The issue is that using an overinflated figure for the scale of the vacancy problem leads to the incorrect conclusion that meaningful change can happen by solving an alleged vacancy crisis. It can't. The scale is not large enough.

It is a convenient issue to misdirect attention to for groups of diverse political leanings. Progressives and wealthy homeowners both can avoid any of the messy realities of needing to permit new housing while pretending as though there's this more politically palatable thing they can do instead.