It really can't be underestimated either for children or adults how much we are dependent on ease of access.
If you're stuck in a room and the only thing you can do is read a math textbook you are going to do it. If you are stuck in a room and you have a math textbook and a novel you now have a choice.
A phone? A phone is everything else. You're putting "the thing we are supposed to be doing" and "everything else" in the same place. I can't even do it as an adult, I need to put my phone on the other side of the room if I want to read something proper.
If you're stuck in a room and the only thing you can do is read a math textbook you are going to do it. If you are stuck in a room and you have a math textbook and a novel you now have a choice.
A phone? A phone is everything else. You're putting "the thing we are supposed to be doing" and "everything else" in the same place. I can't even do it as an adult, I need to put my phone on the other side of the room if I want to read something proper.