"Truth" is a true story about how the fake news media hated the sitting Republican President so much that they desperately ran a story trying to ruin him, only to find out that everything they based their story on was fake. Though it sounds a lot like what happens frequently these days. this specific story is from 2004, and the President was George W. Bush. Instead of ruining his career, it ended the careers of Dan Rather and a team of news producers and reporters. Y'know, back when running fake news actually cost journalists their careers.
For most of the movie, it seems like a straight retelling of the actual shoddy investigative reporting. By the end, though, the movie makes it clear through the characters, that they believe what they reported was accurate, and they were brought down by a Vast Right-Wing ConspiracyTM. The Atlantic's review calls "Truth" "A Terrible, Terrible Movie About Journalism", when it's actually a movie about terrible, terrible journalism.
In the fifteen years since "Rathergate", journalists have learned from his mistakes and work diligently to make sure they have all of the facts before publishing a story.
HAHA J/K ROFLOL!!!
With the invention of social media, it's become very easy for completely false stories to go viral, and since social media and the 24-hour news cycle cause us to have short-term memories, nearly everyone has forgotten the story in a day or two when the facts come out.
(Vast Right-Wing ConspiracyTM is a trademark of the Clinton Foundation.)