I personally say ban tobacco completely, because it's still the single largest cause of medical issues in the US.
Cancer, COPD, Heart Disease, Diabetes, Stokes, etc. All diseases that smokers get at extremely elevated rates. Hell, currently, one out of every five deaths in the US are linked to cigarette use.
But sure, gun control. It's a good idea, but it wouldn't do anything about 20% of all deaths each year.
Anyway, teens are most likely to start smoking via menthols or flavored tobacco. Which is why we should ban them. Because if you can drive that 20% number down, you should.