Yes, the dangers of smoking have been known for a long while. Even back in the 1940s cigarettes were called “coffin nails”.
But that was countered (at least to some extent) by the advertising put out by the amoral cigarette companies. Smoking is cool. And cigarettes are refreshing.
A wise person would see through all that. But the typical 18-year-old kid? Maybe not so much.
I get that it’s a free country. No one forced anyone else to smoke. That doesn’t let the cigarette companies off the hook. IMHO.
That kind of reasoning could be applied to makers of alcoholic beverages. And then we’d have prohibition again, and the proponents of Sharia would rejoice.
There’s a reason why the USA emphasizes personal responsibility. Cigarette advertising has not been a thing for several decades, but that did not stop the demand for tobacco.