On reddit, not so long ago, they were inventing interesting theories about how seat belt laws were justified because without seat belts people would be ejected from cars and kill by standards when their flying carcasses cannonballed through them.
The claim that "it impacts others" is, at very minimum, exaggerated, but just as often completely fabricated out of pseudoscience and absurd movie plots.
Smoking is heavily regulated because there was a resurgence of teetotaling in the late 20th century.