To answer this question, it might be helpful to consider other people in The Outsider who could serve as point-of-view characters.

The story could have been told using a third-person point of view, removing the narrator completely; however, third person would eliminate hearing Pony's authentic voice. Therefore, readers would not understand how much he adores Soda, his complex feelings about Darry, or how the entire group protects Johnny. Taking a step back from a more personal narration would likely lessen the impact of Johnny's death and even Dally's choice to draw police gunfire on himself. I would argue that the first-person narration allows for a more intimate, warm development of the many relationships in this book.

If Pony didn't narrate the story, who would be another likely option? Johnny might be an interesting choice since he is so close to Pony, but he dies before the conflict is resolved; it would therefore be difficult to navigate how the trial and the final rumble play out. Darry and Soda might be good choices, but they don't know Johnny like Pony does; readers would therefore miss the entire church fire scene because Darry and Soda aren't present in that conflict. One of the central messages of the book is that we shouldn't judge people by their appearances, and this message would be a bit lost without Pony, Dally, and Johnny's sacrificial efforts in the church fire. Cherry Valance might be a good choice; she sees the world in much the same way Pony does and also faces great loss in the book. Yet part of the appeal of The Outsiders is hearing from a narrator who doesn't live a privileged life and understanding the way being economically disadvantaged influences relationships and behavior.

Pony seems the best choice of narrator. To shift this perspective would create a different story as it would remove many of the insights that are specific to Pony's perspective.