when florida banned phones from schools, a gold-standard causation study found a benefit of 0.9 percentiles on standardized tests between students who were under the ban and those who could use phones freely. this is about the same impact as studying for a standardized test for 1 hour.

we have had a lot of chances to study this stuff, and the results - like the teen sleep study and the teen wellness studies, both conducted by the same people and NOT capable of determining causation, but nonetheless the best publicized in the media - are real, but they are small.

so the stuff you are saying might be true, but the effect might be so small as to be meaningless. there are bigger threats to society than social media.