Maybe I am taking this too seriously, but I find this kind of parallel unhelpful at best. Smartphones themselves are a huge time sink for a lot of people that is absolutely true and I have no doubt that it can also be considered an addiction.

That being said, smoking is a health problem that has no positive impact at all on our society. By comparison, smartphones can be used as a tool to access a treasure trove of information online. From obscure claims your brother-in-law can make to looking up recipes when cooking, without forgetting learning a language on the bus with Duolingo. Therefore, I think smartphones are above all a very useful tool, and I believe perhaps foolishly that in time we will find an equilibrium that does not include going back to not having one.