I will share you some of my thoughts:
First, you don´t need a smartphone or even a laptop to envy thy neighbour, although I agree it enlarges the problem. Second, even centuries ago wise people knew that you have to be careful with envy, really really careful. Third, envy is not always bad, sometimes it is useful as it can show you something you need to change in your life. Third, happiness most of the time has nothing to do with show off or fakebooks personnas. It is to know what or how you want to live your life and create it. I think young people today seem too naive or not really very well oriented to know these things. Fourth, I am not young anymore, but I think young people today had so different childhoods (or even teen years) from what I had in my past that I am not so sure smartphones (and their possibilities) are to be blamed. By the way, I do not live in US, but I think the same problem is spread around the world in a minor or major degree. Tks for the insights!