This is kind of trickle-down-ish. When you put a dollar in the pocket of an individual, that dollar was fully spent on helping that individual (your point about what he does with it, and whether that counts as helping, still stands).
When you put a dollar in the pocket of a business or institution that "helps people", $0.50 goes to the executives and shareholders, $0.25 goes to all the bloated administrative staff, HR managers, Directors of Paperwork, and so on, $0.20 goes to sub-contractors and sub-sub-contractors who, themselves have executives, shareholders, administration, and at the end of the chain, maybe $0.05 goes to the actual enterprise of helping people.
Yes, absolutely, we need to have a real function in our society that provides housing and care for those who are so impacted by mental health challenges that they will never be able to care for themselves.
I think it's a mistake to think of most homeless people as you seem to - that they're irredeemable and forever broken.
I think you are generally right, but I strongly disagree on this specific point: the working poor would be the most benefitted. They are working, which means they are already taking good decisions and making efforts to improve their lives: money could not be spent in a more productive way than handling it to those gentlemen.
To be clear, this is not about the working poor. I don’t think this would ultimately help them. This is also not about those currently on welfare; I don’t think it would help them either.
The question is, would it help the homeless man living under a bridge or the homeless woman walking around naked at 7-Eleven? Sadly, I don’t think these people can be helped, at least not just by throwing money at them. Even if UBI were implemented, I don’t see them claiming it, and I don’t see them spending it on anything more than drugs and booze.
As far as I’m concerned, rather than implementing UBI, if we were to take that money and use it to implement prison reform and mental health care, it would be far better spent.