The Russo Brothers revealed that the damage caused to The Hulk during Avengers: Endgame is permanent. Especially, when it comes to his arm, which was used to snap the Infinity Gauntlet.
Avengers: Endgame was the perfect swan song for many OG 6 Avengers including Iron Man, Captain America and Black Widow. When it comes to Hawkeye, we already know that a series is being planned with Clint Barton passing the torch to his daughter, Kate Bishop. Thor might be a part of Guardians of the Galaxy 3, as suggested in Avengers: Endgame when he joins Star-Lord for his next adventure. That leaves us with The Hulk aka Bruce Banner. His fate has not been determined but the directors, Russo Brothers reveal that the damage done to him during Avengers: Endgame is permanent.
The Hulk takes it upon himself to put on the Infinity Gauntlet and snap his fingers in order to bring the ones lost during Avengers: Infinity War (2018) back. In doing so, the strongest Avengers loses strength in his arm. While talking to CinemaBlend, Joe Russo stated, “His arm, if you noticed, is a lot skinnier. It’s blackened. So, he loses a lot of strength there.” It’s not just physical damage of losing an arm that is permanent for the big, green monster. It’s also the loss of Natasha Romanoff that has permanent damage on Bruce and The Hulk.