Our oldest got my old iPhone when she qualified for gymnasium at the age of 9.5.
I have configured a quite strict regime via the iOS child control features (max 30 mins per day, no purchases, blocked tiktok.com).
So far it works quite well, it’s enough to keep her connected to her mates, but restricted such that often she isn’t even using it even if she could.
Whenever she can get screentime on another device she is will never stop until external force is applied.
