Look into the work of Jonathan Haidt and you'll start to understand how bad it is. Screens are terrible, notifications are addicting, social media is psychotic and it all plays into the overall social underdevelopment of kids.

I'm not going to say nostr couldn't play a role later in their adolescence as an alternative to legacy social media because it certainly can but that's not necessary until at minimum 16.

But parents who love their kids don't give them phones. Period. If a parent hands their kid a phone or tablet below 16, they simply don't love them enough. I have no problem saying that because I know what it has done to an entire generation or two of kids at this point. 

Homeschooled kids have no reason to need a smartphone. Flip phones don't have the same effect and so would probably be okay if absolutely necessary for contacting parents/friends.

We don't need phones for anything if we choose to limit their use in our lives. We made the choice to join Nostr to escape these addictive platforms, we can make the choice to introduce our kids to technologies as appropriate. I don't plan on letting my daughter drink alcohol at seven and I won't let her have a smartphone until she's at least 16, probably 18.

It's as easy as you let it be.