https://www.health.harvard.edu/blog/poverty-homelessness-and...
Mental health issues can also be alleviated with money. Regardless of what issues a person is facing, they will function better if they don't have to cope with the stress of poverty.
One of the biggest strengths of UBI is that it eliminates the beurocracy and waste associated with determining who "deserves" assistance. The dominant model in the US is expecting homeless people with drug problems to solve both their addiction and homelessness at the same time by themselves before they are deemed worthy of being helped, which needless to say is barely assistance at all. Having a gaurenteed income stream would make it easier to gain a foothold.
I propose it's highly unlikely that a person who is living on streets is doing so simply because they are lazy.
Imagine freezing in the winter or sweating in the summer. How about worrying where you'll find food, staying safe from unstable people or maybe even well off people who attack/kill the homeless. Your claim is that this is a choice out of a laziness and not a mental disorder and/or an inability to get a job due to reasons outside of their control.
What's also interesting is that if you claim it's their choice then not helping doesn't make you look bad.
This means that, if someone does become homeless in one of those communities, it is brief and one-time. The communities were able to achieve this by providing adequate shelters and housing assistance both before and after people lose their homes. They also used person-by-person outreach to make sure they found everyone who was homeless and got them housing.
To me, it seems like that doesn't line up with the idea that some people are predisposed to chronic homelessness/resistant to getting housing.