My parents' generation, the boomers, weren't really aware that smoking was bad. Even if some knew, I feel like it was mostly hidden from them. Look at any movie they'd watch in the west when they were young, people would be smoking everywhere: inside offices, inside cars, public servants at the town hall, etc. Smokers everywhere.
Once the studies eventually came out showing how bad it was, addicted people kept smoking but there's been way less new smokers.
Now I see my kid's gen (so the grand-kids of the boomers): hardly anyone is smoking. It's not a thing among that generation.
As to the gen Xer who used to smoke: most of friends in that segment are now vaping.
Addicts are typically going to be addicts: be it alcohol or tobacco. We're getting a handle on it for the boomers are now dying left and right and it's been a long time smoking ain't being portrayed as being cool anymore.