Socrates would have drawn the line at writing and reading texts.
Not all progress is desirable, of course, and smartphones have their own problems, but same was told about younger generations and internet, TV, newspapers, etc. But those generations grew up out of it and personally I'd argue that smartphone addiction is not only young people problem.
I wish we could, as a society, have a serious conversation about this effect without resorting to name calling ("Luddist nonsense") and straw men ("but what about penicillin?")