Earlier quoted context omitted.
Drownings and ice cream sales also track nicely, but it doesn’t mean it’s the ice cream that’s causing the drownings.
Right, you need a mechanism. (Ice cream makes you fat, fat people can't swim, ergo drownings). Haight clearly outlines the mechanisms by which social media and smartphones have detrimental effects on mental health, see: https://www.youtube.com/watch?v=-l2TdinWoM8
But if drownings had suddenly increased when ice cream was first introduced, that's a stronger suggestion that there's a relationship.
Kids' mental health went off a cliff at the same time that they started getting smartphones and social media.
Something else could be the cause, but we all know it's not, even if we earn our living from it.