While I'm a gen-X'er who bemoans the half-lived lives kids have these days - eyes always on a screen, never aware of the world around them - I have a problem with the phrase "online constantly". Do we even need to make the distinction of online vs offline? What if some kid - and many do - gets their dopamine hit from a game that runs locally on their phone or computer?
Online or not, it is the addiction to dopamine the cute little boxes enable. Let's address that first. Distinctions about "online" or not are beside the point.