What you’re implicitly saying here is that we should wait until there is empirical evidence. That could take multiple decades, and even then will be tenuous at best because you’re dealing with a soft science. At that point the damage will have been done and much harder to address.

If you don’t think attention spans are on the downtrend & that social media has something to do with that, I don’t know what to tell you. I think it’s pretty clear.