well, economic issues. First reason is because you spend money to buy the cigarettes. Second is the government and the tobacco companies buying ingredient form other countries.
tobacco use can kill parents of children making them suffer from depression and anxiety. Tobacco is so addictive so its hard to focus on work while thinking about tobacco 24/7. Tobaccoo does release stress but its really bad for you lungs if you smoke it and teeth if you chew.
I think it has declined b/c if you look at the smoking standards. in 2005 there was 20.5 percent of population that smoked . there was a decline 2020 it dropped to 14 percent of the population smoked