> you can't just exit without losing a big part of the social context because the people around you are eating the same thing.

That's exactly it. The goal is lose a big part of the social context. It driven by rage bait, AI bots, state actors, and a thousand other influences that are predominantly negative. Of course amazing things happen online. However, the good is not worth bad. I'm raising my kids and they will never have a smart phone. Will they miss out on somethings? Of course! They also won't have their attention span destroyed, their ability to be bored and creative in the real world destroyed, they won't have body issues, they won't be caught up in the alt-right pipeline, they won't have their brains fried by content like Mr. Beast which is designed to be as hyper and addicting as possible. Missing out on the current social context is the entire goal. People were happier before it.

This structure expects all of their friends to live in similar systems. Otherwise their friends will talk about games, memes, series at school while your kids are isolated away as they are not a part of the culture and not in the loop.

I think this is only possible if you find a community with similar values, like religious, or hippie, where the focus is put on other things. Otherwise you might deprive your kids of what you want to give them because they will not feel socially connected.