Robert Downey Jr. has played Iron Man since 2008’s Iron Man until Avengers: Endgame. After 12 years of playing the role, fans still wanted to see more of Iron Man, and it is not impossible considering Marvel is going into the franchise’s multiverses.
Downey has mildly touched on this question. During the red-carpet premiere for Downey’s Dream Car, while telling Downey that Tom Cruise was anxious for a sequel to Tropic Thunder, an interviewer snuck in a question about a potential Iron Man 4. To that, Downey joked about Tom Cruise: “Does he want to do that?! Tom, don’t take it!”
Director Jon Favreau gives a more detailed answer. Favreau states he and Downey have yet to discuss a fourth movie:
I’ve talked to [Marvel Studios president] Kevin [Feige] about it to see what they’re up to, but we definitely love working together, and we love these characters. We talk about what it would be, and we always joke about the freak storyline, which is the Happy Hogan storyline, when he turns into a Hulk-like character. We joke about that. No plans, as of yet.
Favreau adds that times are different now than with network television and blockbuster films. Movies could be made for specific audiences using streaming services and platforms. With new technology for streaming services, it is not necessarily out of the question.