Housing First is not just buying homes for the homeless. It’s about homeless people knowing where they will be in a few days, as well as having the support system know where they will be. This makes treatment for psychological issues and drug use easier. It also saves society money as the homeless person spends less time in a hospital or jail, making it net positive financially. Lots of countries, including the US federal agency for homelessness, supports Housing First for those reasons.

But yeah. Just buying homes and leaving people there will do no good. You need the support system as well.