Yea, plus many people addicted to that shit end up doing bad things, Rob, steal, sell to kids, etc.
That’s the same with heroin. At some point you’re addicted as hell and have no money left, so what do you do to get that relief from it again? Prostitute yourself, steal stuff and sell it, rob someone. This is literally an endless cycle. You become more addicted so you have to make more money. Since drug addiction imposes a high risk of losing your job and house you have to become somewhat criminal. The only ways out of this are either 1:dying from the drugs, 2: being able to get off of them(what often is literally impossible without help and even if you manage it without a stable living situation(house, job which both are hard to find as an ex drug addicted homeless person) its not unlikely that you start using them again) or 3: finding a place where you can get them for free. One of these places exists in Berlin where heroin addicted can get free medical grade heroin for free.