Tobacco is a legal substance. Either ban it or allow individuals to choose what bars and restaurants they want to frequent. Leave it up to the marketplace.
In effect what you are saying is that every non-smoker should just stay home. Very few restaurants will implement a no-smoking policy because there’s always the place down the street that allows it. Non-smokers won’t show up so the business is impacted negatively.
If all businesses are non-smoking, then everyone is free to use every restaurant. Even smokers can breathe there.