A lot of shelters have don't allow drugs or alcohol in them. Many or single sex shelters so people with a partner are excluded. Many don't allow pets and for many people their dog is very important.

Also, according to other comments here, many shelters either require houseless people to turn over their belongings (cell phones, medication, paperwork, etc.) to the shelter for "safe-keeping". These belongings can then frequently "go missing", forcing the person to start over from scratch. Alternately, shelters without this policy in place expose the person to the risk of theft from their bunkmates.

The combination of these two factors leads some to self-assess that they're better off on the street.

If you compare to the west coast, it is not rampant. I just moved from Seattle to NYC and the difference is striking to put it mildly.

Fair. I was checking out jobs in LA and was blown away. Was the primary reason I passed on my offers there. Also I didn’t want to give up my public transit