what children truly want, need, and enjoy, is interaction with adults, and the less augmented the reality of the human contact, the real-er it is. build something that doesn't work so well with them, rather than off the shelf something perfect.
If I build and give the kid a display so they can simply stare at it all day without any human interaction... how is that better than the AR on parents phone? It's not, it's worse. (Note, I'm not saying that's what the author actually did, just proposing an option)
The technology here is not the problem. Be in AR or CRT. The problem is how we use it and how we teach our kids to use it.