Iron Man's (Robert Downey Jr.) big Avengers: Endgame. Doctor Strange in the Multiverse of Madness effectively debunks this idea, however.
As seen with Earth-838 Illuminati's successful defeat of Thanos, the Avengers could have taken the villain down in Titan. Since it was isolated, there were no civilian casualties and zero structural damage on Earth. Stark's plan of ambushing Thanos on his homeworld was also smart. It was the first time in Avengers: Infinity War that the Mad Titan was caught off guard, which was integral to his defeat in Avengers: Endgame. Despite having to work with a very small group, the Titan team almost succeeded in their endeavor had it not been for Star-Lord's (Chris Pratt) emotional outburst.
Why Iron Man Had To Fight Thanos On Titan
The threat of Thanos had been lingering on Iron Man's mind since his near-death in Captain America: Civil War. However, after the Avengers broke up, he was left on his own to prepare for Thanos' arrival. Believing that he didn't have the of Earth's Mightiest Heroes, Stark wanted to keep Earth as far away from the fighting as possible. Iron Man also thought that blindsiding the villain would increase their chances of defeating him. Ultimately, Thanos' defeat on Earth-838 proved that Stark had the right mentality.
Iron Man's Infinity War "Mistake" Encapsulates His MCU Arc
Somehow, Iron Man's big Avengers: Infinity War decision summarized his MCU arc. Ever since he survived the Ten Rings' kidnapping in the introduction of the Sokovia Accords and Iron Man's reaction to them in Captain America: Civil War. Iron Mad had the right mindset when he decided to bring the fight to Thanos in Titan, it just didn't pan out the way he hoped for.
Iron Man may have made several mistakes throughout his MCU arc — some more catastrophic than others. However, it's difficult to argue with his commitment to the cause as a superhero. Multiple times, he proved that he was willing to die for a mission. He was ready to sacrifice his life in Avengers: Infinity War when he decided to confront Thanos in a totally foreign setting — a plan that could have worked, as shown in Doctor Strange in the Multiverse of Madness.
