I have no idea how people can possibly identify Marvel as more relatable. It seems to me anybody that brings up that this argument only brings up Spiderman, and that's pretty much it. Like, "Marvel is more relatable, take Spiderman for example!"
Think about it. How can you really relate to Thor? Hulk? Wolverine? Captain America? Cyclops? Professor X? Pretty much anybody in the Marvel Universe that's not Spiderman? It's ridiculous how people think Marvel is relatable, in then their ONLY piece of evidence is Spiderman.
Batman. What really makes him my favorite character is that though he is limited in a world of superhumans, his determination, skill, and genius intellect lets him fight with/against people far greater than him, and be one of the most respected heroes, both in-universe and in real life.