Joe Russo, the director of Avengers: Infinity War and Avengers: Endgame said that Marvel has never been a set plan for the MCU. Joe revealed that it was all Marvel Studios president Kevin Feige’s brilliance act and he didn’t make any plan.
During Sands International Film Festival of St. Andrews in Scotland, Joe Russo told Deadline, “The way it works at Marvel, and I’m sure at some point somebody will talk in detail about this, but part of [Marvel Studios president] Kevin [Feige]’s brilliance is that there isn’t really a plan”
“There’s an idea, but you can’t have a plan if the movie you’re making tanks. There’s no plan after that. Right? So, it’s really about, as the movie succeeded, there was sort of an enthusiasm about well, what else could we do? And then that’s when new ideas would come out, And there was hopes. Oh, we hope one day that we can get to the story, if we keep doing this right maybe we could all get there, you know, like Infinity War and Endgame. But a lot of the stuff was made up in between the movies. And some of the best call forwards or callbacks were thought of after the fact.” he added.
He also told an example that the decision to make Bucky Barnes responsible for the deaths of Tony Stark’s parents – he says this was only “happenstance”. However, it’s a major plot point in Captain America: Civil War, driving a wedge between the Avengers.
Avengers: Endgame ($2.79 billion) at the global box office becoming the second highest-grossing movie of all time and Avatar remains the highest-grossing movie of all time at the global box office with ($2.84 billion).