The media marketplace
The media does not need to be organised by a cabal into operating in a particular way - it will self-organise. In the internet age, news is an efficient, liquid market, with thousands of providers available, all of whom have (mostly) the same information. So how to differentiate oneself? Sensationalism. The rewards for making mountains out of molehills are clear, so, even if certain scrupulous publications resist, many others will not, and soon this elevated sensationalism becomes the new normal. Then, even more sensationalism is required to stand out from the crowd, and the exaggerations escalate, feeding off each other.