I agree 100%...you're post reads like a completely different issue, though. Hence, some of the sarcastic responses.
My 14 yo daughter spends quite a bit of time on her smartphone (music, texting, YouTube), but manages straight "A"'s, is socially active, has many REAL friends, and reads REAL books like there's no tomorrow. IT IS POSSIBLE!! We give her a pass on smartphone use as long as she maintains good grades and gets her chores done. It's the generation...the "iGen". I understand it. The only thing we disallow is a social media account. She just got a Facebook account, but it's just for Speech/Debate (the class requires it) and her Mom is also on it, so she knows it's just for school use.
I got tired of watching our pool of data to make sure she wasn't using too much, so I wound up moving her to an unlimited TM account (piggy-backing with a friend so it only costs us $4/mo as a free 4th line!). We're both happy as I spend less time monitoring data, and spend less money, and she gets "free" YouTube. Everyone is happy!