I'm an introvert. And was as a child too. Talking to friends via msn messenger was my preference. If my mum had of removed my technology I'd of had no way of talking to my friends that was comfortable for me, it basically forces face to face social interaction if you want to talk to people.
Which triggered an anxiety response and made me very tired.
So I imagine banning tech from children will result in introverted children having to be in situations they don't enjoy and not being able to feel comfortable communicating in ways they are comfortable.
It could result in children just shutting themselves away because they dont enjoy the face to face. Which can result in depression. But forcing them to be uncomfortable in social situations can result in serious anxiety and even more discomfort in social situations, if you're forced into something it can create more of a distaste for that situation/ thing.
The times I was dragged to things with my mum, it made me hate parties etc all the more and my anxiety about them got worse.
Whereas if it's something I chose to do for myself, it had less of a negative effect on me than if it's something I was forced into.
So if introverted children prefer texting, messaging etc then you take that away from them, it can result in them having to do things they aren't comfortable with, which can have an effect on mental health. As it's forcing them into different things they don't really want to be doing.