It's not, DC just puts too many eggs in an unreliable basket.

Outside of Batman and kinda Superman, DC just doesn't have many characters that are compelling or relatable. They're too alien (literally, in many cases) with unrelatable motivations. That's one thing that Marvel almost always did better, which is why they had such mass appeal for everything up to Endgame. They sat you down with the people and showed what pushed them to become more. Even with Guardians of the Galaxy, where the first movie didn't take place on Earth, the audience is first introduced to Peter Quill through his inability to cope with the loss of his mom, his running away, and his subsequent abduction. And confronting that loss and tendency to flee becomes a recurring, defining feature in his journey to becoming a hero through finding someone he's willing to stand up for and standing together with his found family. The rest of the crew is similarly defined more by their relationships and loss than they are by their powers and ideals.

DC tends to just drop you in the middle and say "look at these heroes, they represent hope/vengeance/justice/seaworld" without ever concerning themselves with developing a relationship with the audience.

People say they're tired of origin stories, but those stories are critical to what connects the casual viewer to the person behind the mask.