Smoking cuts your life expectancy by something like ~10 years. Most of those smoking deaths are people who've already smoked 30+ years; there's not a lot we can do to prevent those deaths now, even if they all stopped smoking tomorrow. They'd still get cancer and everything else at higher rates. We've also done a pretty good job at lower smoking rates, especially among young people. Sure, we can ban or restrict tobacco more (maybe we should) but the "public health crisis" is mostly done.

Opiate addiction cuts life expectancy by ~35 years. And getting them onto safer drugs would save lives very immediately. There's stuff that could be done, and everyone knows it, and it's not happening. That's the public health crisis.

edit: and, yes, also, opiates are also more socially destructive, due largely to the criminality.