Speak for yourself, but the internet has made me smarter in many ways, not dumber. This has been my choice, sure. I can tell you however that I would never have read half of the interesting and intellectually stimulating thoughts and ideas without the internet.
Indeed. I think the internet is worth a std deviation. Before I was 25 or so, I spent the vast majority of my time bored, and the dozens-to-hundreds of questions I idly wondered about each day were largely unanswered and unanswerable, in aggregate. The world has changed, and while I can handle a few days or a week offline, I don't want to, if I can help it; the internet is where the answers are.
That's sort of true - but I've noticed a much more troubling phenomenon. My questions are increasingly tending to be those that are answerable by the internet. I used to regularly wonder who I really am and why I'm here - now, I've given up on all that and primarily look up interesting stuff on Wolfram Mathworld.
The internet can still help with the "who I am" and "why I'm here" questions. There are so many readily available viewpoints out on the internet that I can use to help shape my worldview. Certainly many more than the predominantly white, Christian home state.