https://streetlifesolutions.blogspot.com/2018/05/seattle-sta...
The US needs to provide a national health care system. Our current system is actively part of the problem.
Homeless services need to do a better job of providing "opportunity," not just charity. Most homeless services actively help keep the problem alive, a la The Shirky Principle.
https://streetlifesolutions.blogspot.com/2019/08/give-man-fi...
https://streetlifesolutions.blogspot.com/2018/07/the-shirky-...
Please note that I spoke of opportunity, not jobs nor jobs training programs. Lots of job training programs et al actively limit opportunity. They don't want their participants to get too uppity or ambitious.
People with chemical addictions will not go to shelters because shelters don't allow you to be drunk or high.
So shelter beds go unused, and people shoot up and drink in parks, on sidewalks, and on busses.
Shelter bed usage in Seattle runs at 90% as of last year, with low reported use rate before that being an artifact of bad reporting rather than reflecting actual conditions [1].
[1]: https://www.seattletimes.com/seattle-news/homeless/qa-with-p...
There are several thousand shelter beds that go empty each night in LA County, include nearly a thousand in Skid Row, because the shelters have sobriety requirements and most of the homeless would rather be high than housed, especially in the summer.
In the winter, it's usually easier to convince the homeless to knock off the contraband and use the shelters, especially after the first dozen or so weather-related exposure deaths.
Here’s the laundry list of things Seattle has tried and is trying: https://www.seattle.gov/homelessness, https://www.seattle.gov/homelessness/addressing-the-crisis
These cities have in turn some measures and initiatives that are proven solutions that reduces homelessness. Note that not all of them could work in Seattle, but some of them might.