I just read this article about how RDJ pushed for more screentime and had Cap3 changed from a proper sequel to the Winter Soldier to Civil War. So, to quote the article “ The smart money was on a third film focusing on the Winter Soldier’s rehabilitation: a redemption arc for Bucky Barnes and closure for Steve Rogers. (…) So if Civil War turns out to be an unsatisfying conclusion to The Winter Soldier, fans have an all-too pragmatic explanation to blame: Robert Downey Jr.’s contract negotiations.”
I don’t thank you for being so close in character to Tony Stark that you don’t know when it’s time to take a step back and let the others shine, Mr Downey Jr. Iron Man is an interesting character, but he already has the most screen time in the MCU, between his own movies and his huge lead role in the Avengers movies. I’m mad that screen time had to be taken from characters who deserved a proper development.