Too much screen time?

Okay so I work at a restraunt and I'm always surprised by how many children I see, from little toddlers up to probably 8 year olds who have a phone or a tablet in front of them, and they even have headphones sometimes while the adults eat. I work at a casual breakfast place but I'm always taken aback by how often I see this. Today I saw two siblings in highchairs, both holding phones with headphones watching cartoons while the adults talked and ate. The kids coildnt have been more than two years old. I always see this and it males me sad. Isn't that the age you should be learning from the world around you?? learning how to be a human an in society basically? Do you think it's okay for kids to have screens in front of them so the adults can talk?