>One study that does not propose alternative views

Why is proposing "alternative views" required for a critique? If we're discussing what caused diseases pre-germ theory, does that mean we can't point out the flaws in miasma theory because no "alternative views"?

>and cites "selling a lot of books" comes off to me as someone with an agenda. No thanks.

Well clearly you only read the first two sentences (or first paragraph?), because it cites multiple studies:

>These are not just our data or my opinion. Several meta-analyses and systematic reviews converge on the same message2–5. An analysis done in 72 countries shows no consistent or measurable associations between well-being and the roll-out of social media globally6. Moreover, findings from the Adolescent Brain Cognitive Development study, the largest long-term study of adolescent brain development in the United States, has found no evidence of drastic changes associated with digital-technology use7. Haidt, a social psychologist at New York University, is a gifted storyteller, but his tale is currently one searching for evidence.

Not to mention "selling a lot of books" isn't even the critique, it's that it offers a seductive explanation:

"... because Jonathan Haidt is telling a scary story about children’s development that many parents are primed to believe"