We don't lack housing. We lack affordable housing.
Some of the homeless have jobs and families. They just can't afford to rent or buy a home.
Some of them are insane. Many are addicted to drugs and alcohol. Treatment is needed for them more than high tech security.
I saw something a while back about an Orlando developer planning buildings full of 200 sq ft apartments. Hive homes of a sort. I think that's more viable than individual tiny houses, but a lot can be done with modular housing these days.
Good coffee, good weed, and time on my hands...