There’s a reason why Cap is the one that gets to shout “Avengers Assemble!” when the troops need to be rallied. He’s the hero everyone in the Marvel Universe looks up to and aspires to be. He’s pure. He stands for what’s good and right at all times, no compromises. That’s why Captain America spearheads that battle cry. When he calls, every hero listens. This has been the case ever since scrawny Steve Rodgers was given the equivalent of a Tosh.0 “Web Redemption” during Operation: Rebirth in World War II.
Captain America is the quintessential patriot; why else would he wear that star on his chest, that “A” on his forehead, and carry around that star-spangled shield that he’s really, really good at throwing? Captain America might not have the power-set of someone like Superman, but that doesn’t stop him from defending his home till his last dying breath. In a nutshell, Captain America is the alpha and omega of inspiration in the Marvel Universe.