The pair actually shot another version of the scene on Vormir that would have had Hawkeye and Black Widow fighting off Thanos’ soldiers together before Scarlett Johansson goes for the cliff.
Jeremy Renner previously addressed the scene on social media, admitting it was a difficult day to film but one of the best.
Instead of Endgame including a final battle alongside each other, it was cut down, likely due to the movie’s pacing.