I couldn’t help but feel that so many of the characters were in the story to do one thing and one thing alone. the nameless Arab never speaks, Salamano is never relevant outside the context of his dog, and the judge, Celeste, and the robot lady all only make momentary appearances. as far as more major characters go, the priest only acts as a priest, granted a nervous and emotional priest. Mersault’s mom is dead for the entirety of the runtime of the book, and most of the other background characters fulfill their role in the story with little depth to their own person being explored.
One could argue that this is a consequence of the book being in first person. Meursault doesn’t strike me as a particularly emotionally intelligent person. he is incredibly observant of behavior, but as far as emotions go he seems a step removed given Meursault’s own emotional behavior. this is compounded by the fact that the three characters that I would say have the greatest degree of depth to them, Maman, Raymond, and Marie, are the closest people to Meursault, and so he can see their own depth more clearly.