While Marvel's promise on introducing the real Mandarin of the Ten Rings as the character's proper MCU version and seperate new character and villain to the franchise is still the main reason for Marvel to extend Downey's contract for more additional films in Phase 4 as well as seeing how the Mandarin he is yet to confront is capable of taking him on with the power of his ten magic rings,
other major reasons regarding our needs of having Robert continue reprising his role as Iron Man after Infinity War Part 2 involve;
His popularity as the armored avenger along with his looks, and funny sense of humor
While the real Mandarin is certain to be the main villain in Iron Man 4, other villains from the Iron Man comics like Crimson Dynamo (Valentin Shantov), Ezikel Stane, Titanium Man, Ghost, and Fin Fang Foom need to be brought out onto the big screen as well for other sequels after the fourth installment Marvel claims that finding a replacement for Downey as Iron Man is impossible With the Masters of Evil yet to be confirmed for MCU Phase 4's Avengers film, we can't have the Avengers take him on without Iron Man Plus what's the point of watching more Marvel Cinematic films if Marvel doesn't have RDJ reprising his role as Iron Man and with Iron Man 4 and more sequels developed for Phase 4 So while we are still waiting for Captain America Civil War to come out, feel free to get in touch with Kevin Feige right now and convince him to have RDJ's contract renewed for Iron Man 4 and more films after Avengers Infinity War Part 2 so that we won't miss seeing more of the character in the films as well and making sure we see him take on the Real Mandarin as well as many other enemies he has fought in the comics After all it's never okay to get people's hopes up after causing a setback and nobody wants to put up waiting for the people at the studios to reboot the franchise so please before any announcements on the Phase 4 films are made, get to it!