What happened to Joss Whedon? Where did he go? Well guess what he ain't coming back. Joss Whedon was the director of Avengers and Avengers: Age of Ultron. Joss Whedon stop directing the Avenger series after Avengers: Age of Ultron. The reason why he stopped is he said he didn't have what it took to direct the next upcoming Avengers movie Infinity War part one. His exact words Every movie I have ever made has been an ensemble piece of increasingly enormous proportions. That many balls in the air, it’s only going to get bigger with 'Infinity War.' I’m not going to be able to give it what I would need to. - Joss Whedon. He gave this huge role to The Ruffalo brothers. He had a huge beat down after he directed Avengers: Age of Ultron he just said it was not that good.
“I was so beaten down by the process,” Whedon said. “Some of that was conflicting with Marvel, which is inevitable. A lot of it was about my own work, and I was also exhausted.”
Whedon blames himself for the narrative that the project wasn’t perfect, and said he had failed.
After all he did do a good job with the First Avengers movie.