Spoilers for A.X.E.: Avengers #1 by Marvel Comics
In his Celestial judgment, Iron Man just learned that if he had kept his Iron God armor a few more weeks, he might have been able to save the Marvel Universe. In A.X.E.: Avengers #1 by Marvel Comics, Tony Stark gets judged by the Progenitor and has to face his greatest fears and past. When he encounters Thor, he's told that he had what it takes to save the Earth from the Celestial but made the mistake of abandoning his most powerful suit of armor too soon.
Iron Man recently became a god in the pages of Marvel Comics, as the hero's attempts to stop Korvac from gaining the Power Cosmic resulted in him gaining the powers himself to stop the villain. As the Iron God, Iron Man lost control of his powers as he dangerously shaped the Marvel Universe in his own image while killing his closest friends for trying to stop him. Thankfully, Tony Stark was unable to do the damage he caused, but now that he's facing Celestial judgment, Iron Man is forced to relive his darkest moments while being told if he had kept the powerful god armor, he could have saved the day.
In A.X.E.: Avengers #1 by Kieron Gillen, Federico Vicentini, Dean White, and VC's Cory Petit from Marvel Comics, Iron Man ventures inside a Celestial in hopes of stopping the space god from destroying the Marvel Universe after deeming via judgment that the planet wasn't worth saving. However, while inside, he faces his own judgment, including being forced to confront his time as an Iron God, where he killed War Machine. When Thor confronts him, Iron Man is told if he kept his god powers, he could have saved the Marvel Universe.
Iron Man's God Powers Likely Would Have Created More Problems Than Good
While it's possible that Iron Man's Iron God powers could have helped save the Marvel Universe against the Celestial's judgment, it's just as likely that Tony Stark could have reshaped the world for the worse before the Progenitor was awakened. Iron Man's god powers corrupted to the point where he killed his closest friends, so there's no telling what he could have done if he had kept the armor for much longer.
Iron Man's god armor might have been the lesser of two evils in a situation against the Celestial's judgment. Still, despite Tony Stark being told he could have saved the Marvel Universe with his Iron God powers, he could have been just as destructive a force as the space god. Plus, there's no guarantee it could defeat the Celestial. Ultimately, it's for the best Iron Man didn't have the Iron God when the Celestial attacked; otherwise, it could have spelled an even quicker doom for Earth.