Addiction isn't an on/off switch, it's a spectrum. They can cut back over time - there would probably be a pretty dramatic cutback at least initially, but supplemented with (probably copious amounts of) nicotine gum, it could get them into the spot where they might actually be able to kick the habit themselves.
Nor am I suggesting we take cigarettes from, what, $10 a pack (gross oversimplification since IIRC my brother bitched about New York costing $15 a pack while Tennessee is more like $7 or
to $50 overnight, since that would be widely derided as 'something something federal overreach, something something freedoms, something something my body my choice'. But gradually phasing in higher and higher tariffs over a decade is something fully achievable.
Although obviously for maximum effect either the first or second jump needs some real teeth, like a 100, 150% tax. But subsequently jacking it up 20% here, another 25% there...I think that's doable.
Of course, I also think we should do that will alcohol, since that kills a shitload of people every year too, but that would be just too deeply unpopular. Republicans and Democrats alike would probably get together to lynch me if I proposed that, since it would affect white guy beer just as much as white girl wine, and they're the ones who lynch people.
It'd be the unifying moment this country has been praying for.