So an endless parade of soup kitchens it is.
It's not the case that Daly City, Mountain View, Pleasanton etc, have all solved the problem without telling SF how to do it. In reality, the surrounding cities simply don't have the problem for various reasons and environmental factors, so they don't need to solve the problem in the first place.
Its a Ponzi scheme first and foremost, housing simply cannot outpace wages, it's impossible. When it all comes crashing down is someone elses problem though hey :)
Since piles of people dead from exposure isn't a risk, the city doesn't have the same motivation to build shelters like a New York does, so they kick it to the side.
The citizenry gets concerned with poop on the street, but once it's bodies, they really expect the government to do something.
3 part answer:
1) my understanding of the political lean of the city is that the government is the great social savior.
2) most private groups who take care of the homeless and otherwise destitute havehistorically had a religious affiliation.
3) private groups have to deal with the same real estate prices as everyone else, and because of 1 and 2 and the general skepticism of religion by the citizenry, they won't be given any tax breaks or land price cuts, meaning they simply cannot afford to setup service.
It really is a self feeding system of misery-but-not-enough-to-kill-you all the way around.
This does not appear to be true for San Francisco.
Hot weather and good infrastructures so you can live in the street.
Liberal so you are not bashed out by the cops.
Rich so you can beg for money.
Many water points.
Strength in number.
What's it like to dumpster dive in the city with the most billionaires per capita?
OTOH, drug dealers, too, obtain economies of scale by concentrating drug users in close physical proximity (and vice versa). It seems to be plausible to assume that the easy availability of drugs is itself causally contributing to drug use and drug addiction.
[1] A. Badiani, Is a 'general' theory of addiction possible? A commentary on: a multistep general theory of transition to addiction. https://www.ncbi.nlm.nih.gov/pubmed/24888430