This is a logical fallacy. If you increase the dosage of mercury, it'll eventually be deadly. In the same vein, smart phones, social media, etc are entirely different beasts to books, radio and even television.
I don't understand this line of thinking. Sure, it may not be the literal end of the world, but that doesn't mean that it won't cause a lot of damage before people 'adapt'. People have always adapted to wars, but that doesn't mean that the world wars weren't absolutely catastrophic.
And while I don't think that smartphones will 'destroy you', I think there's a good chance that it can both be very corrosive in all sorts of manners. I think smartphones are a lot more potent at sedating people and making them detached than novels ever could hope to be, which can have a very harmful impact on society at large.
At least there's some ability to interact with a smartphone, there's absolutely none of that with TV, and yet society survived.
I think it's kinda too early too judge (only ~60 years of widespread adoption and in this time the TV landscape has changed massively), but I think there's a pretty good chance that 'tabloid style' TV has caused a good deal more damage than the yellow press has.
> At least there's some ability to interact with a smartphone
Sure, but that also makes it a lot more addictive. You generally won't see people who are glued to their TV 24/7, but with smartphones that's not uncommon.
> yet society survived
Again, I'm not saying that society will just implode on itself, just that these things can do a lot of damage.
Thank you for the answer though, I appreciate consistency when examining the impact of media.