This isn't just exclusive to the USA, we have the same problem here in Canada. There was a shift from housing those with crippling addiction and mental health issues to making them all outpatients, which itself, appears to demonstrate some mental health issues with those in charge, as clearly people who are unable to self-govern aren't going to be well-suited to free-roaming. They don't take their medication, or start self-medicating with street drugs and boom, they are a total train wreck.
We've got the same issue here locally, we've become a "destination" for addicts and homeless because of our facilities. The problem is that few on council or in control want to take that next step to re-introduce institutionalization, they want to just keep handing them needles and drugs and having hundreds of paramedic calls a month to revive them and claim this is "working". The few that have suggested bringing back dedicated treatment and care facilities get chastised for not being "progressive" enough. Yet it would seem that those self-describing under the progressive umbrella, are oblivious to the fact that doubling down on what hasn't been working, continues to make the problem worse.
The problem is the "proper care" part, at least around here, never comes. I'm sure most are familiar with the 'ol "If you build it, they will come" and oh, they have. But they are not receiving proper care, and eventually, they OD and die because no amount of clean needles, untainted drugs or safe injection sites solve the problem. I heard a horror story yesterday from a councillor candidate that they don't take the tainted drugs away with them, so these people just take the clean drugs and sell the deadly ones to somebody else, who dies on the church steps or in an entranceway.
And of course that doesn't get into the danger of people who should be institutionalized and are wildly unpredictable, roaming around unsupervised and resulting in issues such as those described in the OP. Is it truly compassionate to allow people to self destruct, giving them all the tools to do so, then calling this "no harm"?