It's not just about feeling smart and superior, it also helps them feel invulnerable. People victim-blame smokers who get lung cancer because they don't want to think about the chance they might get it too.
You're not wrong, but you're missing how people become smokers. "Approximately 90 percent of all smokers start before age 18; the average age for a new smoker is 13." [1] A momentary error in childhood judgment (to the extent that isn't an oxymoron) quickly becomes an addition. "Inhaled smoke delivers nicotine to the brain within 20 seconds, which makes it very addictive—comparable to opioids, alcohol and cocaine." [2] Once they're hooked, it's very hard to quit [3], so it's often a life-long addiction. And that's before we even get into all tobacco companies have done to hook people.
So even as a life-long nonsmoker who absolutely hates smoking I think there's a lot of unnecessary victim-blaming for smokers.
Yes, non-smokers can get lung cancer, too. But at a far lower frequency.