Anyone who's familiar with large retirement communities will notice that very few of them smoke.
Smoking tends to kill people off before they become very old.
And the few who do smoke and live to a fairly old age usually suffer from smoking related problems. Emphysema is one of the most horrible conditions smokers live with (if they don't die from cancer or heart attacks first).
I quit at 45 after 30 years of smoking. The benefits to my health and life in general are well worth it. It's probably the best thing I ever did for myself.