tl;dr: We need more data and better data to draw reliable conclusions. This far the closest we can come is
"The authors’ overall calculations did find a statistically significant negative association between technology use and well-being: more screen time is associated with lower well-being in the young people surveyed. But the effects are so small — explaining at most 0.4% of the variation in well-being — as to be of little practical value."
"The authors’ overall calculations did find a statistically significant negative association between technology use and well-being: more screen time is associated with lower well-being in the young people surveyed. But the effects are so small — explaining at most 0.4% of the variation in well-being — as to be of little practical value."