I work with a few parents who spend the day texting/messaging their children.
Their children in school are being distracted and their learning is being hindered.
The parent at work is being distracted and their productivity and focus is being hindered.
It's a lose-lose situation all-round. When I was a kid I managed to get through the school day without looking at my phone (went through during the transition to smartphones, first iPhone).
I can't comprehend where we go from here if people use their phones this much. One of my colleagues probably sacks off 2 hours or so of their working day constantly checking their phone, and it's vibration patterns on the desk distract me working adjacent to them.