I think a larger more unnoticed social harm is the damage it does to single payer/socialized medicine. When you only have one insurance pool every person receiving healthcare related to smoking is funding that could have gone to treating diseases that aren’t as easily preventable.
The same goes for things like diabetes, which is absolutely destroying medicare. Right now one out of every three medicare dollars are being used to treat a completely preventable disease for the vast majority of those inflicted with it.
I think that if you want to smoke or drink tons of soda, that’s fine. But we shouldn’t be lessening the scope of healthcare coverage for other people just because of your bad habits. Either the industry making the money needs to subsidize the healthcare cost of their consumers, or the consumers themselves need to do it.