The measurements are always wrong. Volunteers tell people to lie on the point in time surveys so programs supporting them (or claiming to support them) keep getting funding. In the west coast cities the majority are from elsewhere and it’s easy to confirm if you actually talk to some of them and learn more about the backgrounds of people at the camp. They are there because not only are they tolerated and can break the law without consequences, but they also get free needles to help their habit.
> but they also get free needles to help their habit
They're not getting free needles to "help their habit", they're getting them so they don't re-use or share. Because what's more difficult to help than an addict? An addict with a communicable, potentially fatal, illness.
I am an ex-paramedic. I've lost track of the number of times I've administered narcan, gone to ODs, seen the sheer disaster of cotton fever (https://pubmed.ncbi.nlm.nih.gov/23528959/). Free needles isn't encouraging people to keep their habit going, it's a means of not adding one more route to death's door.