Society is addicted to money, violence, vanity, illusions and delusion. They are the misery which drive people into escapism, comfort, brief respite.
I've been there and imho drugs/alcohol are far less damaging than the alternatives, if there even is an alternative available. I don't see much hope for the future for anyone really, and that's by design.
Most who are self-medicating have tried all society's fake cures and set goals, and realised they're all a crock of shit designed to keep them on the plantation.
Deaths of despair may be via drugs/alcohol, but they are because of enforced misery, violence, abuse and betrayals.