The problems is drugs. Like the man in the OP’s original story. He was educated, had a good job, had a home and then started using meth and lost it all. He could move in with his father or live in a shelter which someone who is just without a home would do. The people on the street are (in the main) drug addicts. Drugs are a scourge and a more severe crackdown on their use and distribution is needed.