There have been repeated studies and examples where homeless people have simply been giving a house and basic living wage, with no qualifiers on who can receive it based on mental health or drug use. Every time this is done people thrive and pull their lives back together.

It absolutely is, at its core, a housing problem. Provide basic humanitarian safety and stability and people can pull themselves out of the darkness just fine.

Edit: the “evidence and outcomes” section of the housing first Wikipedia page speaks for itself: https://en.wikipedia.org/wiki/Housing_First