Dude should visit my dispensary, which is always full of grim-faced Vietnam vets using canes and walkers. They are very much the demographic that is dying in unprecedented numbers from opioid and alcohol abuse.

American Medical Association agrees with you. From Vox:

The best study done to date, published in the Journal of the American Medical Association, reviewed the research and concluded that pot — again, including its smoked form — can effectively treat chronic pain and muscle spasticity. The study didn't rule out other potential medicinal benefits, but those were the two it found the best evidence for.