What

I don't get it.

I think the implication here is that the internet is not making us any smarter. If anything, we're less mature now than we were before.

I made many stupid mistakes and there is no evidence. The same cannot be said for kids today.

It's because many adults today can't hit the traditional milestones of "maturity" after higher education. No job promotions, no money, no house, no children because no money or house. There is really a sociological stunting of maturity going on that has nothing to do with the internet (not directly at least). But many of these same people are actually smarter FOR not bringing children into the world without resources.