The Purpose of Batman in the DC Universe

Batman is without question one of the most iconic and famous characters to have ever been created, and I would say a modern mythological symbol. He arguably has more content written about him then literally any other fictional character ever made. 

Now personally when talking about DC Superheroes I'm a massive fan of Superman and a pretty big fan of Wonder Woman and Doctor Fate. I'm not a big Batman person, and the personal reason is when reading superhero comics I wish to read about demigods, about modern mythological heroes confronting the extremes of reality, the sorta abstractions that we normally don't see confronted in stories. I don't usually read Street Tier characters like Batman, Green Arrow, Black Canary etc. because those heroes feel much more "Earthly", much more bounded by what you might consider the conventional. Not all the time certainly, Batman in particular has some very otherwordly stories about confrontation with the absolute, but in general that's the reason.

However some people have taken a similar logic and gone to an extreme that I think is unwarranted and is a general very shallow reading of the character of Batman and his place in the overarching DCU. You'll see comedic skits about Superman and Batman and they will question why does Superman/The Justice League etc. even need Batman? Batman doesn't have powers, he's just a rich guy in a suit etc. 

This strikes me as a shallow read on the character. Now this is a question that can be answered from two perspectives; one is the "in-universe" perspective of assuming these characters are real, and the other is the "out of universe" perspective of talking about the characters as fictional characters. It's really easy to say out of universe that Batman is just purely a wish fufillment character. He's a leading member of the Justice League but he is a normal human that you could be. 

I don't find this a very compelling argument for two reasons. One is that there have been a lot of wish fufillment characters and none have stood the test of time better then Batman. Batman remains popular over 80 years after his conception and 60 years after the formation of the Justice League. Such a base appeal is not likely to explain that. The other reason it doesn't fit right with me is that Batman is actually depicted as the least human personality wise, relative to the other members of the Justice League, at least in any depiction that's happened even remotely recently. Superman is depicted as a bit of a naive but compassionate Kansas Boy, Wonder Woman is depicted as an honest and idealistic but competitive and stubborn warrior, The Flash is depicted as an impulsive goofy hot-head who tends to run himself into corners etc. Batman on the other hand is the logical practical planner of the team, often more cold in his analysis then any other core member of the JLA.

This brings me to why I actually think Batman is an important member of the JLA and the DCU as a whole. The DCU is a universe of living archetypes, it's what I think of as the distinguisher between DC and Marvel. DC's characters are closer to being pure archetypes and Batman is one of the purest archetypes. To compare him to Superman; Superman is the Inhuman trying to be Human; Superman is that which sees us from outside and sees the greatness of humanity, who wants to be like us, who wants to embody our values and our strengths. Batman in contrast is the Human trying to be Inhuman, after seeing the brutality of man and the pain of weakness, Bruce strives to become something beyond human, a symbol that can strike fear into the hearts of man, something beyond what a simple human like Bruce Wayne can be.

This to me is the reason both in and out of universe why Batman is so important to the Justice League. Humanity in the DCU is a noble, powerful thing and Batman is the human archetype taken to it's extreme. When people say Batman is the "Peak Human", they don't mean he is peak human in our world, he's Peak Human in that he's the absolute for what a human is in the DCU. In Universe Batman is the Human Example that the JL strives to be like and to fight for, and out of universe Batman is a major part of the overarching DC Storyline of Humans being the Next Gods. Batman is the Human Archetype, he is human in the paradoxical sense that he is ever striving to be more then human, he is the human in the ascent of humanity, human in the aspect of human's ability to rise above. This is why he is so important in universe and out, because he represents what will be the next race of Gods, both literally and metaphorically in the DCU.

The DC Universe's main plotline seems to be the overarching story of the rise of humanity to be the next world of the Gods as has been foreshadowed and alluded too many times. If that is then Batman's dealing with the strange world of the JLA, represents humanity's dealing with the strange world of the abstract and supernatural that surrounds the Earth.