No. They haven’t. When across the board smoking bans were instituted did heart disease fall 60%? Did non-smokers stop dying of lung cancer, mouth cancers, and other cancers? The studies are pure bullshit. While smoking is bad for you, it’s not as bad as it is made out to be, and the studies prove it.
The correlations are clear. Just because cancers can and do occur otherwise doesn’t negate the obvious connection.
It’s worse.