I’m guessing there’s a bit of breathing room at the lower end of the system - there will be people who become drug addicts or have major mental health breaks and lose everything.

And ideally we have good safety nets that find these people and give them resources and treatment, but some people will refuse everything and end up in bad situations of homelessness due to their drug and/or mental health crises.

And even in a society that forces those people into attempted treatment programs, there will still be a bit of time in between their issues manifesting and them going into treatment/therapy/confinement.

To have “zero homeless” you’d need to preventatively intercept these people before they become homeless and force them into confinement in treatment facilities and mental hospitals essentially. And that’s a dangerous game because you’re essentially taking away someone’s freedom preemptively before they become homeless

Depends on your definition, but not everyone is necessarily happy (or at least, happiest) living under a particular roof.

Housing is a privilege, not a right, and not a requirement. Except, being a free country, in jail.