It turned out to be a simple thing, really: there just was not enough demand for facts to sustain profitable news organizations. CNN laid off a large group of science writers. Newspapers closed. As blogging became easier, the ratio of people writing to the facts actually reported reached an historic high. And then went higher. It was a bubble waiting to pop.
Some folks were happy to hear that all religious people were nuts. Facts were fabricated, distorted, and filtered to support this viewpoint. Others were eager to hear about how distorted and fabricated is science. More facts were fabricated to support this. The market provided facts for which there was demand.
As it turns out, there was no real demand for the truth. The truth was too messy to neatly fit into any one theory or viewpoint. It was not simple. It didn't really support anything as simplistic as conservative or liberal, material or spiritual distinctions. Tolerance for the facts required a kind of tolerance for ambiguity and lack of resolution that most people found distasteful. TV news was always secondary to the drama, comedies, and entertainment on TV. But once newspapers dissolved in the early part of the 21st century, movies became the preferred form of news: by contrast to actual events, movies offered revenge for the oppressed, engaging and attractive personalities, discernible plot lines, and resolution in less than 2 hours. The way that past generations had clung to tribal myths and persecuted those who might advocate the empirical method, the developed world began to cling to movie myths at the expense of reality and people who struggled to report it.
In this sense, the 21st century did turn out to be the virtual reality century. What few had considered was that this virtual reality would use humanity's oldest operating system: the belief systems and imagination of groups.
It was this decay in thinking and disconnection from facts that, finally, undermined society. Not war. Not climate change. Not discrimination or financial collapse. It was, instead, simply a growing disinterest in the facts. Pity, really, because it had been a wonderful civilization.