If the state lets social housing be purchased then its stock of rentable housing diminishes until it needs to start renting out private properties, which means

If the state lets social housing be purchased then its stock of rentable housing diminishes until it needs to start renting out private properties, which means the taxpayer effectively paying investors' mortgages. If instead the state invests in building a certain amount of social housing that can be maintained and used long term at affordable rent for people under a certain income, you would take inflationary pressure off the private housing market. I'm not an economist but it seems obvious to me that paying private investors rent in order to provide short to medium term social housing is counter productive in the medium to long term, and it's something for example Ireland is doing a lot, contributing to Ireland's housing nightmare.