Robert Downey Jr. is the godfather of the Marvel Cinematic Universe, since his charisma as Tony Stark/Iron Man started this whole adventure with Iron Man in 2008. RDJ recently talked about retiring his jersey alongside buddy Chris Evans. Their characters clashed in Captain America: Civil War, but there's a brotherly love there that definitely extended off-screen. Heck, RDJ even custom-made Evans a Captain America Camaro.
Speaking to Disney twenty-three magazine (via Comicbook), Robert Downey Jr. opened up on his decision to get off the Marvel Cinematic Universe bus with Chris Evans:
We had to get off. We opted to, and knew it was part of the job to get off the bus while it rolled on to other destinations. There's something very sobering about it. I'm glad he and I will be there to welcome others as they retire their jerseys.
They knew at some point they'd have to graduate from the MCU. That said, if the actors really wanted to continue, Marvel Studios would've surely loved to keep them. (Like Chris Hemsworth, who is back in the game for Thor: Love and Thunder.) Instead, Robert Downey Jr.'s Tony Stark sacrificed himself to save the world in a heroic death at the end of Avengers: Endgame. Chris Evans' Steve Rogers/Captain America got to live, but he also exited the MCU by passing the shield on to Anthony Mackie's Falcon. He is confirmed to be done playing Cap.
Chris Evans talked for a long time about leaving the MCU after Avengers 4, and his character was the one predicted to die in Endgame. Robert Downey Jr. recently talked about wanting to distance himself from the character of Iron Man, comparing his time with Marvel to being a trust fund kid. Sure, you make a ton of money -- especially if you're RDJ -- but you don't want to get too cushioned or comfortable or forget that you are not actually this superhero character.
Now that RDJ and Chris Evans are off the MCU bus ... what's the next destination? They both have other projects in the works, and Evans has talked about wanting to pull a Tony Stark and have his own wife and kids.
Robert Downey Jr. spoke more to the Disney magazine about his legacy, turning to his fellow Avengers for real-life hero inspiration:
I really don't need to look any farther than my co-stars. Mark Ruffalo is an activist, Chris Evans is a diehard American and proponent of true democracy. I don't really have the gumption, the skill set, the drive, or the humility either of those guys do.