Although we have the necessary information, many people, especially politicians, have other agendas. A lot of people die from tobacco use. They are not only old people, but also the middle-aged. Exposure to tobacco is most likely to be problematic when you are a teenager. In addition, young people are often rebellious and like to experiment.
Tobacco is an easy legal substance to experiment with.
Tobacco cessation has to be far more effective means to young adults, who already are addicted to tobacco. The social environment is crucial. Countries are using legislative mechanism to prevent smoking and this has a snowball effect. The more you restrict the places and possibilities to use tobacco, the less people will smoke. Two or three decades ago, smoking was socially acceptable behaviour.