Dear down voters: it should be obvious that just because smoking is not literally guaranteed to destroy your lungs, and you can find plenty of counter examples, it's still a very good idea to warn people that "smoking will destroy your lungs".

And it would have been a good idea to do that back in the 50s when doctors were calling it safe without the science to back up their claims. "You have no evidence" is what you say to justify avoiding something suspect, not what you say to justify consuming it!

Sure, counterexample: my grandfather. Hyperbolic claims like "it will destroy your lungs" are counterproductive in the long run; far better to give a measured, accurate description of the actual level of danger.