https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4363846/#__ffn_...
Long before that publication, however, Wright SC (et al) published a paper still referenced today in toxicology textbooks entitled "Nicotine inhibition of apoptosis suggests a role in tumor production" [ FASEB J. 1993; 7:1045-1051 ]
Studies here: https://www.selfhacked.com/blog/28-proven-health-benefits-ni...
Also, because once you get addicted, nicotine withdrawal is bloody awful.
For all you that haven't done it: smoking causes pleasure. A fast, intense and repeatable pleasure.
I quit smoking years ago and of course I strongly discourage people from smoking, it's very bad for the health, etc.
But spreading disinformation is not the way to fight it.
Edit: BTW, the first times you do it are the worst. While you get used to the smoke.