> Even if tobacco use was decreasing, that doesn’t mean something else wasn’t increasing in its stead. It could have been ridlin, opioids, meth, etc...I’m not sure what the popular bad stuff between 2000-2010 was, perhaps some younger HN readers could fill us in.

As someone who used to work in drug policy during this exact time period and has a very strong grasp of the facts on the matter, I can assure you that your speculation is entirely without merit. Teen tobacco use decreased. It didn't pawn off those would-be tobacco users onto other drugs, as if drugs were some fully fungible entity in teenagers' minds. Teen tobacco use decreased, full-stop.