A drug addiction problem is a fast track to homelessness for just about anybody.
And drug addiction will prevent anyone who's homeless from getting out because it sucks up any income that could be used to level up in any way.
Not a single one of these people was ever homeless. My wife is a 20+ year engineer with a top secret clearance.
The homeless people I meet, on the other hand, completely run the gamut. I met married couple in their early 20s a few weeks back that stopped to talk to me about skateboarding and showed me pictures of their dogs. I showed them pictures of my cats. They lost their jobs, had no family support, and didn't want to go to a shelter because they've have to give up the dogs, so they lived in a tent down by the cargo rail. Another guy I met the week before that was obviously completely insane. He emptied a bottle of hot sauce on me and threatened to stab me for making noise on a public bridge at 8 AM an hour past sunrise and waking him up. I had at least 8 inches and 80 pounds on him and he was trying to fight me anyway.
I don't think the reasons boil down to something as simple as they're all drug addicts and drug addiction is a guaranteed path to homelessness. Even for the openly crazy, antisocial people that are obviously who the San Francisco tech crowd are actually bothered by, I don't understand what the proposed solutions from the anti-housing crowd are. If we don't house them and don't treat them, are we throwing them all in prison for life? Executing them? If we don't do either of these things, they're living animals that have to eat, sleep, and shit somewhere. You might prefer it be somewhere you'll never see it, but where? What is a solution that isn't just making it someone else's problem?
Morally we should house and treat them. That is a huge resource draw, since if you just throw them into low barrier housing, you just get a bunch of bad crap happening in whatever unfortunate neighborhood you choose for that. So we need millions of dollar in treatment per case, and maybe we can fix them? Like a 20% chance. Those are a high amount of resources for a low chance of success, ideally we should spend the money anyways but practically we can’t afford it. We could just house them with a social worker like Finland does, but 1 social worker per 4 residents is going to cost about the same and doesn’t even try to fix their problem.
So morally you are right. Maybe in the future when we achieve a post scarcity society we could do that. Today we could focus money instead on helping people before they become addicted to drugs, we would get much better bang for buck of limited resources. I think it is a bit dangerous to teach our kids that we can and will be able to save them even if they try fent (or something unknowingly laced with fent), because that likely isn’t true ATM.
Making it someone else's problem is what most of the country has chosen. As this thread notes, SF's homeless population is increasingly from outside the city. Trying to resolve this at the city level is not sustainable.
Yes, ideally we have infinite resources and we can solve the drug addiction problem without becoming China or Singapore and just stigmatizing the problem to death. But we don't, and dumping in 95% of our funds allocated to homelessness to what is really a drug addiction problem, and barely seeing any progress in either problem, is eventually going to wear the public out.
Also homelessness is a fast track to addiction problems for many people. If you feel that bad you are prone to do anything to make it less bad even briefly.