Not so sure about this; would need to read the whole paper. "No evidence" could just mean that causality could not be proved (admittedly very difficult to prove), which doesn't mean that there is indeed no causality. I'm not sure I'd trust this researcher any more than I'd trust any other single paper on the topic; and the preponderance of papers has shown there is a link though the details may be in dispute.
What is not in doubt is that there has been a sharp increase in teen mental health difficulties in recent years: look at this 30% increase from 2017 to 2021[0]. This also coincides with a significant increase in social media use among young people. Correlation is not causation, but there haven't been many other theories as to what might be driving this change.
Phone usage increase, sleep quality decrease, quality of life decrease for the worker class, increase in inequalities (gini coefficient increase) ... There is a lot of confounding factors here.
What is not in doubt is that there has been a sharp increase in teen mental health difficulties in recent years: look at this 30% increase from 2017 to 2021[0]. This also coincides with a significant increase in social media use among young people. Correlation is not causation, but there haven't been many other theories as to what might be driving this change.
[0] https://www.cdc.gov/healthyyouth/mental-health/mental-health...
I'd also want to know where the funding for this meta study came from.