No, that’s not the reasoning. This argument focuses on the effect, not the act itself. There are more stakeholders than just the person performing the activity. It’s an utilitarian argument stating that the choice on the matter needs to benefit the majority. You can look at this dilemma from all sorts of moral and ethical perspectives. You state that the act itself is bad and laws should apply on all similar situations even if they cannot be compared. That is one way to look at it but it would make life pretty grim, unnecessarily complicated and unpractical.

As for the decision of individuals to engage in dangerous activities. It is indeed their freedom to do so as long as they are capable to make that choice and harm no others (which is easily done). However, the governments that individuals are subjected to have the moral duty to keep its people out of harm’s way, as far as it is reasonably possible, through laws and regulations. It is up to governments how they apply those laws. And they will try to keep as many people as possible happy, which is pretty much an utilitarian approach. Likely the ones that bring the most cash.

Tobacco should be banned because the harm to others (many) outweigh the satisfaction of the user (few).

The satisfaction of the user that comes from the addictive nature of nicotine and is an avoidable, artificial factor. Addiction causes withdrawal symptoms (pain) when not fed. Feeding the addiction alleviates this pain which would not exist if not addicted. The net gain equals zero. The only reason smokers like smoking is because they get hurt if they don’t. It is unethical to put people in such a position.

Also, smoking and second hand smoke hurts society and individuals alike. With a rise in disease rate comes more medical care costs which, in my country, is paid from taxes and insurance paid for by other people. Also, a lower work efficiency (through disease and smoke breaks) can affect a nations economy. On the other hand, mortality rates increase causing a shorter life span what equals less costs.

However, a tobacco ban limits the freedom of smokers to do as they please. Smoking on the other hands limits the freedom of non-smokers to live in a smoke free environment (disregarding other pollution focusing on one thing at a time) as well as the freedom to not pay for the self-caused harm of others.

Problem is, how would you go about setting up such a law affection millions of people. Addicts would surely rebel against it as they will definitely experience withdrawal symptoms. Maybe distributing on prescription until the whole generation died out.

In the end, a nice bonus would be that farmland used for tobacco can be used to grow much needed food to alleviate worldwide food shortages. What adversely can cause overpopulation as another problem.

In my opinion keeping people from becoming addicted is the absolute goal rather than limiting current addicts. The choice to smoke is not always fully conscientious. Despite laws forbidding acquiring and use of tobacco, minors do smoke and get addicted before passing the age of consent affecting them throughout their lifetime. While the majority start at a young age with the idea of being cool, curiosity or succumbing under peer pressure, it is unlikely an adult would start whilst knowing the effects of smoking. As it is unlikely anyone would want to be dependent on something.