If there's a fundamental difference between the weaselly narratives constructed by Fox News and the psychedelic screeds Thompson put out, it's that most reporters aren't making it explicit that their stories are fully personal, opinionated interpretations of true events -- they record some isolated facts, sample a few quotes and make vague references to public sentiment to back up any narrative they need. But they present all of this as objective information. This was happening well before H.S.T. (see "yellow journalism") and happens outside the U.S. too (see Daily Mail).
Thompson's approach was (1) a veil of entertaining literary showmanship over (2) complete, self-accountable interpretations of the events being covered. He was clear that his stories were subjective, and that freed him to explain exactly why he felt the way he did about Nixon, drug laws, Southern culture, etc.