You display extrovert in wanting to change other people for your needs, its less important what they are. Using the internet for wanting to change other people to not use the internet as much will never work anyway. They are the majority, so you have to adapt or decide if you can live with it.
Really? I thought you already agreed that introversion/extroversion only has to do with where you get your energy. Do you even know where you are going with this yourself anymore?
Your attitude to change sounds very defeatist. Personally I thought this smartphone behavior would stop once the novelty wore off, but it hasn't happened yet. I think it's the addiction mechanism kicking in. Addiction to constant validation. Awareness of this must be raised. It needs to become shameful, just like gaming addiction is.
Introversion and extroversion also impact how people interact and socialize. I travel around my region by car a fair bit, and can happily sit quietly for hours on end. This tends to unnerve several of my overly extroverted friends who can't understand how I can just sit there without having to talk or say anything. It becomes even more apparent when I'm traveling with two or three other strong introverts and an extrovert, especially compared to trips without the extrovert. Guess which times "uncomfortable" or "awkward" silence gets mentioned? I've taken eight our drives where the only words spoken after the first fifteen minutes were about directions, and whether anyone needed to stop for a bathroom break.
Introverts usually don't complain that other people are 'socially inept' because they don't insist on talking endlessly about useless junk no one gives a damn about. That is something extroverts like to whine and complain about. It is however, their problem, not mine, when they're uncomfortable about a silence, and if they're going to act like a jerk about it then I'm not going to lift a finger to help them.
It is perfectly acceptable socially to remain quiet in a car, because everyone's face is facing the same direction and you are all waiting for something else to happen when you reach your destination. Sure, you answer if someone talks to you, but there is no need to start a conversation if you don't feel like it. You should inform your friends of this. And I once again inform that this is not an introversion/extroversion thing, so you can lay it to rest.
Does it? Is it a real problem that needs to be solved, or is it just a social trend you dislike?
It may seem like fun and games to you, but addiction is no joke. Not only is it a personal tragedy for those who become a victim, what is worse is that it seems to become more and more common. If it becomes too common, it can have both economical and cultural consequences for the entire society. And it is also annoying.