Did the people in this thread even read the article? It suggests that the effect of eating potatoes or wearing glasses on childhood well-being is greater than the effect of screen time.
That's what the article says, but the definition of "well-being", and the methods, are not explained. Even if the results of this meta-study are reliable, that doesn't mean they rule out all possible negative effects of screen time.
The point is that there is little to no evidence that screen time is bad (or good), just a lot of speculation. The argument against screen time is essentially the same as the one used against GMO foods: "it's new, so it's probably bad." Obviously that's not a strong argument but people in these comments seem to be accepting it without reflection.