Vaping is almost harmless compared to how many diseases smoking tobacco causes and how much it makes a person stink and how much it makes buildings stink and how the tar builds up on walls.
Same way chemo cures some cancer but is pretty damaging overall. But when the alternative is death, anything else is better.
PSA: Don’t start vaping if you don’t smoke, it’s lame. Don’t start smoking either, you’ll regret the health issues, earlier death, and money wasted.