That (Youtube and Instagram etc. ) contributes, no doubt, but not a deciding factor. Way to check: is it possible to produce smart people from kids using electronic educational media without restrictions? May answer is “Yes, there is a way to do that” as in “no law of nature prevents this from happening”

But education is veery fucked. Not just in US. For many decades, in many ways. And this is not going to be fixed with changing print books to laptops, vice versa or with any other superficial way of pretending to care. I wish enough people understood this