Yeah, uh, that's a hell of a debate there. And what is lost is not always so; assuming it can be found again.
Could be found again but it would be a bold move from marvel.. Iron Man isn't the most powerfull marvel superhero by any chance, in fact, he is one of the less powerfull bitches there is.. If you want power in the marvel universe you have 3 ppl and only 3:
For the good side common heroes: Thor. He destroyed a planet with a punch, literally. He is stronger than The Hulk. But of course in the movies they like iron man so they nerfed Thor a whole bunch... (Also nerfed iron man, but even with his nano suit iron man is not powerfull enough to even try to fight Thor)
For the good side Not well known entities: Living tribunal. He is fucking omnipotent. Thats it. Nothing can defeat it. NOTHING,
For the bad side common known villains: Apokalypse.. I dont think i need to say anything about him.. He fucking destroyed X man alone.
For the bad side less known: Galactus.. He eats fucking worlds for a living... EATS. WORLDS.
And for the neutral more badass piece of shit there is that crapped over humanity over and over again except when he tried to help: Beyonder. He is one step ahead of the living tribunal. But just that is enough juice to destroy everything known (including iron man)