It makes a lot of sense when you realize who builds and brings capital. Debeers for an extreme example.

Take mental illness. A mentally ill person with more resources can get the care they need, but someone who is poor can soon find themselves on the street. And homelessness itself is quite stressful, and can produce or exacerbate mental illness as well as drive people to drug addiction.

Homeless people are just like the rest of us, with their own basic human needs, and just like everybody else are trying to navigate their world as best they can.

The big question I have is how do you help people who refuse to be helped? That’s an ethical dilemma not necessarily a $ question.

News flash: nobody does/does not do drugs based on legality.

The Rat Park experiment showed that rats in enriched, social environments consumed far less drugs than isolated rats, highlighting how environment strongly affects addiction.

In Defending the Undefendable, Jeffrey Moussaieff Masson’s chapter “The Pusher” argues that drug dealers, often vilified as destructive criminals, play a complex social role by supplying a demand that already exists. He suggests that punishing them does little to stop drug use and may actually exacerbate harm by driving the trade underground, increasing prices and danger. Since demand for illegal drugs is inelastic, higher prices directly leads to increase in petty crimes like theft that are often motivated by addiction. I.e. addicts wouldn't have to steal as many catalytic converters if drugs were pennies per day instead of hundreds of dollars. And it's only expensive because it's illegal. It's kind of ironic.

Dark speculation here, but addiction may even be an evolutionary coping mechanism, providing just enough short-term reward to keep individuals alive when life feels unbearable. The alternative to addiction might be even worse given e.g. an unusually strong biological emotional response to a (possibly accurate) negative assessment of their personal reality.