I think that most of the people that are on facebook now were not "on the internet" at all ten years ago. Maybe as consumers, but not as content producers.

One could of course argue the value added by a typical facebook post, but let's not pretend that tens of millions of people were setting up blogs to keep their grandparents updated with pictures of their grandchildren.

Blogs are still here, I follow many of them and RSS is alive and kicking. Most people that had blogs before and produced long-form content are still there. The only problem is that the advertising well might go dry.