Marvel Studios could have easily made a fourth Iron Man movie if they were interested in it, but they were not and they didn’t need to do it. I’ll never look back at the 23 movies that Marvel made in The Infinity Saga and question why they never made Iron Man 4. They managed to move forward the story arc for the character flawlessly through movies like Civil War, Infinity War, and Endgame.
But, if you’ve questioned why Marvel Studios didn’t choose to make Iron Man 4, Avengers: Endgame writers Christopher Markus and Stephen McFeely explained why in an interview with Vanity Fair. McFeely said:
“Whether you like all of the 24 movies or not, the capital that Marvel built up allowed them to do things like make a movie starring a raccoon and a tree, right? You would’ve already had Iron Man 4 if it was any other studio. But they decided, No, we’re going to take chances on all these other things. To put a flag in the ground and say, We’re going to end something and take characters off the table, is, I think, kind of daring, but selfishly it was really great for us.”
“It needs an end or it loses meaning. The end is what cements the thing, to actually sew it together and bring it to a crescendo, and yeah, take people off the board, finish their arcs. If Tony made it out the other side, and Iron Man 4 was waiting there, you’d be like, [shakes head] One too many…”
It makes sense as to why Iron Man 4 never happened. Hell, I liked Iron Man 3, let’s be fair… I don’t think we would have missed it in the MCU if it didn’t exist. I’m sure Marvel thought of it at some point. I just think about what kind of story they would have told if they wanted to go that way.