[Don'tMessWithTexas]

Lower premiums do not necessarily cover the increased risk. Costs are still shifted.

[Just another Joe]

Lower premiums do not necessarily cover the increased risk.

Don't you mean higher premiums?
As for increased risk, smokers tend to use less, insurance, medicare, SSI, etc, than do nonsmokers over the long term.
There is documented proof of this.
Smokers may tend to an increased risk over the short term but a decreased payout over the long term.