I believe smoking increases your risk of getting lung cancer by about 20%[1]. It's definitely significant, but plenty of regular smokers manage to die from something else. I'm pretty happy about the repression of public smoking though, because I find the odor of cigarette tobacco revolting and also prefer to not have my risk of lung cancer even moderately increased by second-hand smoke.

Annoyingly, it's hard to find good figures on relative risk for smokers and non-smokers, probably because of the current public health fad of dissembling to attempt to encourage desired behaviors. All I can find is that for the total population lifetime chance is 1/15 for men and 1/17 for women[2], with some weasel words about smoking increasing risk, but no actual quantification.

[1] It's true that most people with lung cancer are or were smokers. But it's also true that most people with lung cancer are over 65, and they're from a period where most everyone was a smoker or exposed to smoke regularly. That's a pretty major confound. Over the next few decades we should get better data due to the relative decline in smoking making the effects of choosing to smoke clearer.

[2] https://www.cancer.org/cancer/lung-cancer/about/key-statisti...