Marvel Cinematic Universe fans almost got to see Thanos throwing the decapitated head of Captain America. That was briefly the original plan in Avengers: Endgame, according to screenwriters Christopher Markus and Stephen McFeely. Between the end of Infinity War and the conclusion of Endgame, MCU fans were already on an emotional rollercoaster, but it was nearly much, much worse and violent. With that being said, we did get to see The God of Thunder decapitate The Mad Titan, so there was still some beheading included in the final cut, so to speak.
Christopher Markus and Stephen McFeely appeared at Comic-Con today and shed some light on their practices and ideas that almost made it into Avengers: Endgame and Infinity War. One of their original ideas was to have a time-traveling Thanos carrying the decapitated head of past-Captain America. In the scene, we would see the 2014 version of Thanos entering the main timeline of 2023 while destroying the Avengers HQ. From there, he would have thrown down the head of 2012's Steve Rogers.
The Avengers: Endgame screenwriters admit the idea was a bit too "extreme" and that the idea was axed right away. However, Christopher Markus believes it would have been "awesome." While some MCU fans might agree, that would have been a pretty heavy scene, which may have run into trouble with the MPAA when it came time to get a rating. Marvel Studios likes to push the envelope of the PG-13 rating, but they might have drawn the line at decapitating one of the most beloved superheroes of all time.
On a less gory note, Captain America's ending was there from the beginning. "From the very first outline, we knew he was going to get his dance," says Stephen McFeely. His heroic sacrifice is what ended up getting him the life he always wanted with Peggy Carter. However, McFeely admits to that he started to second guess himself when trying to figure out the logistics. He explains.
"On a separate subject, I started to lose my barometer on what was just fan service and what was good for the character. Because I think it's good for the characters. But we also just gave you what you wanted. Is that good? I don't know. But I'll tell you, it's satisfying. He's postponed a life in order to fulfill his duty. That's why I didn't think we were ever going to kill him. Because that's not the arc. The arc is, I finally get to put my shield down because I've earned that."
Avengers: Endgame is currently the second highest grossing movie of all time and has its eyes on taking down James Cameron's Avatar. As of this writing, the movie sits at $2.782 billion, while Avatar sits at $2.787 billion, so there's only a little bit further for Endgame to go. Maybe if they would have included the decapitation scene more people would have flocked to theaters. The comments from Stephen McFeely and Christopher Markus were first reported by Comic Book.