Smoking laws are restrictions. You can't smoke within 30ft of an eating establishment or in a car with a child. You want to go home and chain smoke yourself to cancer? Have fun. Likewise, you couldn't restrict smoking at home typically.

Seatbelt and helmet laws are a condition of using property that isn't yours (the road). Likewise for drivers licenses and minimum road hours.

A good case here is the Texas anti-sodomy law (Lawrence v Texas) that was struck down in 2006(!) after being used to go after gay men. Here Texas made claims it was acting for the public good, SC ruled the state had no presence on a private matter outside the public eye.