Warning! Spoilers ahead for Batman/Superman #9
World's Greatest Detective, a founding member of the Justice League, and one of the most focused and determined superheroes the DC Universe has to offer. In the first few pages of Batman/Superman #9, Batman shares some insights as to why he's the best hero to protect the people of Gotham, and much of it has to do with the people of Gotham City themselves.
In the first few pages of Batman/Superman #9 from writer Joshua Williamson with art by Clayton Henry, Batman is without notifying the Man of Steel. Things quickly get out of hand, as Batman soon discovers that Skull is not fully in control of his faculties, including his explosive powers. Thankfully, Superman is alerted to the situation courtesy of his super-hearing and quickly flies to Gotham to assist the Dark Knight.
While a crazed Atomic Skull is certainly interesting enough in Batman/Superman #9, the insight from Batman about his own city of Gotham is definitely noteworthy. In the beginning of the issue, Batman talks about how after every big super-villain attack and threat to the city (of which there are several), all of the experts predict that the City of Gotham will experience some sort of mass exodus, and that that attack will be the final straw for citizens, and that they'll pack up, grab their families, and move somewhere supposedly safer. Batman shares that in actuality, the opposite occurs.
According to Batman, the experts are always wrong because they don't know Gotham. He says that the people in his city are strong-willed and stubborn, and that they often get more people who arrive to the city after a large attack, trying to prove to the world that they're tough enough to survive Gotham and its dark shadows. Why else would they stick around after terrible events such as when Bane recently ruled Gotham in Joker War, which is sure to cause massive chaos and destruction? Despite Batman talking about the people he protects with what feels like pride and iration, his claim also seems like a converse reason for why he's the perfect hero to protect them. Who is more strong-willed and stubborn in the DC Universe than Batman himself? Who is as determined and focused, constantly proving to all that he can survive whatever is thrown at him? This line of thinking makes sense, seeing as how Batman is a Gothamite himself.
Bruce Wayne is a true Son of Gotham, having grown up there, which is kind of unique if you think about it when compared to his fellow Justice Leaguers and the realms they usually protect: The Flash, while based in his home of Central City, often traverses beyond his home to other realities and timelines thanks to his speed. Batman is truly the best superhero to protect the people of Gotham because he's one of them himself and holds the majority of their same beliefs and values.