Smoking tobacco is something people have done for centuries. Pretty unlikely that we'd eliminate it in a few decades.
smoking tobacco is bad, but smoking cigarettes is much, much worse because of all the extra shit that's added in to make them even more addictive (and more carcinogenic) https://en.wikipedia.org/wiki/List_of_additives_in_cigarette...
We've been harming children for even longer
Europeans started smoking tobacco in 1492 and it spread super fast.
It probably can't be eliminated completely, but if they slowly make it illegal for young people to start the habit it can be reduced