I think you’re missing the point, which is that screen time is (or, the implication is that it is) an unhealthy waste of time.

It’s uncontroversial that sleep is necessary and healthy, walking is necessary and/or healthy, working is (mostly) necessary (regardless of whether it’s healthy), and blinking is necessary and healthy.

The implication is that there’s almost zero about screen time that is healthy or necessary, with some exceptions.

And that this has become recently common. Prior to the Information Age, it was less common that we spent this much time on screens.

People that did were called “couch potatoes”.