I do some work with the homeless in chicago, and the people you see living on the street are, by and large, not drug addicts.
In Chicago, drug addicts are transient-homeless. They're in and out of shelters as they get evicted or kicked out of a place, but they find somewhere new (indoors) to live. Some may be periodic homeless.
The chronic homeless in Chicago are usually physically and mentally disabled, and while they may drink, it's not substance abuse that keeps them from holding down a job and getting shelter.
One of the recent encampments we visited had an interesting story. It sits on what was the future site of a factory, and the group had all gathered there to work as labor for the construction. However, the builders found contaminated soil, and were working on a mitigation plan when covid hit, and these guys (and a few women) have been living there ever since. They recently called the police because someone who moved in to camp had stolen propane tanks from the neighborhood grills.
They're not all like that but it's a much different scene than a warm weather city's homeless camps. Edit: One thing that makes this plain is the lack of sharps in the chicago homeless camps. Most of the time you won't see orange caps!