Canada

Switzerland has this policy since the beginning of the 90's with drug users. The quality of life improved to a level that retirement homes prescribe opioid to some resident.

It's an amazing win-win-win situation. The overdose rate plunged with people being in a good health condition and finding jobs despite their addiction. The life expectancy of this group is sky rocketing. It costs a fraction to the society as people are contributing to the society itself.

Regardless, it is an important study to disspell stigmas that have existed since the beginning of private property.

But it is still important when it comes to housing. This argument of homeless people being untrustworthy with money has undoubtedly already worked it's way into that debate. If people won't trust them with money, why would they trust them with an apartment? Canada and the US don't see them as "worthy" or responsible enough to be given anything, not even food. Look at what an insane process it is just to apply for food stamps in the US, and that applies to low income folks as well as homeless people. Everyone is considered a criminal until they can prove otherwise, and they're rarely given that chance

Not that I think academic research will make much of an impact. Research from the social sciences consistently debunks all kinds of common, harmful beliefs, and yet is still often ignored by policy makers and average people. It's depressing as fuck that there are academic researchers spending years on studies like this, convincing people to fund them, getting paid dick by their universities, and still a bunch of assholes who have never set foot on a college campus get to just cut it down by saying "oh, well, that's what I heard." And then move on with their lives while homeless people continue to suffer for no reason. This is an example of the far reaching impacts of devaluing education I guess.

think of the landlords. if you give people free housing what will landlords do? you can't expect them to contribute something!

There have been studies which tried that too, there was one in the city I'm in where they gave free housing to homeless people but it didn't go super well. IIRC the issue was that a fair few of them also had underlying addiction/mental health issues which kind of derailed things (one person set up a tent and started a camp fire in the living room, as an example.)

Not that I'm against giving money or homes to the homeless of course, but I think it also needs to go along with an investment in infrastructure and support for addiction, mental health and that sort of thing as well.

Also just to head off any pedantic replies: I'm also not saying that all homeless people are mentally ill or drug addicts, just that money and houses won't solve everything, and we'd get a lot further with proper infrastructure underlying it in my opinion.