The following contains major spoilers for AXE: Judgment Day #5, available now from Marvel Comics.
Judgment Day has brought every single human, mutant, and Eternal on Earth to the edge of damnation, and all that any of them can do in the hopes of staving off oblivion is their personal best. Not only is the recently resurrected Celestial Progenitor judging the world as a whole, but they are also judging each individual being alive on their own merits. As unnecessarily meticulous as this might seem, there is still one person who is capable of making the whole world a little more worthy. With a few simple words, Captain America has made each and every single person on it one of Earth's Mightiest Heroes, and all of them are better because of it.
AXE: Judgment Day #5 (by Kieron Gillen, Valerio Schiti, Marte Gracia, and VC's Clayton Cowles) finds the X-Men and Avengers desperate for any possible means of saving the world now that the Eternal Eros' best attempt has failed. While there is still time for the heroes to launch a calculated assault on the Celestial's one vulnerability, their plan isn't a surefire way to end Judgment Day. Rallying every last person on Earth, however, might be enough to tilt the scales in their favor at the last second, and there is only one way Captain America knows how to do just that. With Jean Grey broadcasting his message around the globe, Steve Rogers deputized everyone left as an Avenger before sending the call for all of them to assemble.
This might not be enough to sway the Progenitor's opinion of Captain America as a failure, but it is absolutely a testament to how much sway he holds over the rest of the world. As the psychics monitoring the state of the general populace can tell, the rage and anxiety that had swept over the globe are now directed towards the Celestial who has come to judge them rather than at their fellow denizens of Earth. Even Captain America's detractors and enemies are fully aware that he doesn't say anything he doesn't mean, and almost nothing means more to him than being an Avenger.
Steve Rogers has lived through some of the most terrifying and glorious eras known to man as a soldier, and he has fought his way across even more of them as an Avenger. The very concept of Earth's Mightiest Heroes is something so dear to Captain America that when he felt he wasn't worthy, he simply walked away. When others have pushed the edge of what the Avengers stand for, he has been the one to push them out. And, when staring down the rapture, he has found the strength to put the fate of the world in everyone's hands in a way the Progenitor never could.
It isn't just that Captain America has made Avengers of the entire world that makes this moment so profound. It is the fact that he has put every ounce of faith he has behind humanity in the most literal way possible. Of course, whether it be complete strangers or his closest allies, Captain America has always been the first to offer a second chance because of his belief that people can choose to be better.
After being judged unworthy, surviving total annihilation at the Progenitor's hands, and calling the previously deceased Celestial out for all to hear, Captain America has done all that there is to prove how deeply his faith in the world runs. That alone doesn't mean every person on it is truly worthy of being an Avenger, although it does help to showcase that everyone does has the potential to be. At least, so long as they are given the opportunity, and considering the state of the Marvel Universe right now, there has never been a better time for that than the present.