Perhaps one of the most powerful scenes in Avengers: Endgame was the battle between Hawkeye and Black Widow on Vormir, as they fought it to decide who would sacrifice themselves for the Soul Stone. It was a unique scene. We're used to seeing heroes fight for their survival, not for the right to die.
It turns out that scene was part of a reshoot. Initially, Hawkeye and Black Widow were supposed to be fending off an attack from Thanos, but that scene was cut, reshot and replaced.
"It was a tough scene for us to shoot," explained Renner, at Ace Comic-Con over the weekend. "It's a reshoot we did about six months ago. The original was a lot more complicated, with an attack by Thanos. This was just us."
Which made perfect sense. No one would have batted an eyelid if Black Widow's eventual death had been the result of some sort of battle with Thanos, but the scene that made the final cut was a far more an interesting way to resolve that scenario. It had more impact and, for me, was one of the most memorable and interesting sequences in the entire movie. Good call!