As a person who had difficulties relating with other kids back in school (and that also had his first phone later than many other guys) I think that in my case having a smartphone and unrestricted internet access already in elementary school could have made things worse for me, as I would have been even less incentivized in learning how to relate with other kids. Sure, I could have been happier in the short term, but I think my social skills would have been worse long term. Of course this is just my opinion and in my specific case, but I generally agree that waiting until middle school is a good idea. And of course this doesn't mean that parents don't still have to do their job at informing their kids about potential issues of social media and the Internet on general, but I think that an older kid is better equipped to deal with those. At such an age, even 2/3 years make a big difference in maturity.