True, a kid who has had too much screen time is not good, just like a kid who has had too much lunch is not good. That doesn't make lunch bad, it just means the kid needs the right amount.

Screens can be helpful for kids (mine have learned a ton from Khan Academy and other online tools), but kids will have different thresholds. Some will only be able to learn a little from screens because they can't work independently. Others can learn a lot. Blanket statements like "kids lean better from humans than machines" are not helpful. They obscure the fact that there is typically one teacher for 25 kids, whereas there might be 25 screens. Even if a screen is only 1/10 as good as a teacher, it could be that learning from a screen is better than learning from a teacher (who is busy with your classmates almost all of the time).

My kid learned more math when she was doing AoPS for 2 yrs than when she was in class listening to lectures she already knew, followed by worksheets she had already mastered. Machines enable much more differentiation.