Also how much content they contain. You could go through a new comic in 20 minutes flat. Game Gears could last a few hours. Android phones provide endless content.
this is a true statement, but idk how different it really is for the kids. when i was a kid i would happily spend hours rereading the same garbage star wars expanded universe books over and over and over, even though i had basically memorized the plot. with the abundance of content, i doubt today's children would be as satisfied to revisit the same thing so many times, but i also doubt that they waste much more time than i did.
They provide endless _new_ content. I still don't see how the kids of today aren't learning social skills through observing their parents because mobile devices are sucking their attention away.
My point is that the nature of what kids do at parties hasn't changed in any significant way to support your original claim that there are "so many basic things we just don't learn how to do anymore".