Child with phone addiction

I have a relative who will be on his phone until he is literally sick and will throw up because he hasn't eaten and he's been staring at the screen for so long. Kids with ADHD tend to hyperfocus on certain things and that's what seems to be going on here. This is just my opinion, but I don't know that he would miss out on too much if he didn't have a phone. He is pretty young to have his own phone, and could probably get by without one, especially if he is more engaged in the real world without it.