Avengers: Infinity War and Avengers: Endgame, as the Avengers, New Avengers, Guardians of the Galaxy, and more ed forces to stop Thanos.
Avengers: Infinity War saw Thanos finally collecting the Infinity Gauntlet and all six Infinity Stones, while the MCU heroes did their best to stop him from doing so and later from wiping out half of life in the universe. Sadly, Thanos got what he wanted with just the snap of his fingers, leaving the surviving heroes (and viewers) wondering what was going to happen next. Avengers: Endgame saw the surviving characters coming up with a plan to acquire the Infinity Stones and stop Thanos, making way for the time heist. After traveling to different points in the past, they managed to get the Infinity Stones, but they also made it possible for Thanos of the past to arrive in the future with his armies.
Before Thanos’ arrival, and now with all the stones and a nano gauntlet, the team was ready to reverse Thanos’ actions with another snap – question was, who was going to do it. Thor volunteered as he’s “the strongest Avenger”, but Tony made him understand that he wasn’t in good condition to do so, and so the Hulk (now merged with Banner’s intelligence, making way for “Smart Hulk”) stepped up. Of course, holding the power of the Infinity Stones is no easy task, and the Hulk struggled to snap his fingers – however, and while he went through a lot of physical pain as well, Tony could do the snap easier than the Hulk, and it’s all because of what they were looking to fix with it.
On their quest to get the Hulk’s snap, Tony reminded him that he had to bring back those who vanished after Thanos’ snap but without changing anything from the last five years, and he did so, but he also tried to bring Natasha back. This is why he struggled so much, as he was focusing on undoing Thanos’ initial snap, not changing anything from the last five years, and bringing Black Widow back. Even with all his efforts, Natasha wasn’t going to come back as she didn’t die as a result of the snap, and it’s the same case for Gamora.
Tony, on the other hand, had a less complex goal in mind and was aware that he wasn’t going to be able to bring her back, so it was easier for him to snap his fingers and finally get rid of Thanos and his armies. While Captain America: Civil War and Avengers: Infinity War, giving full closure to her time in the MCU. The Hulk had good intentions, and they came with a prize, as his arm was left severely injured after the snap, but there were things that just couldn’t be fixed, not even with the power of the Infinity Stones.
