Report writing is significant in the UPSC exam, particularly for the Mains where candidates may need to articulate their analysis and solutions clearly. Good report writing showcases a candidate's ability to present information concisely and logically, which is crucial in governance roles. It also reflects essential skills like critical thinking and effective communication, both vital for aspiring civil servants. Properly structured reports can influence decision-making processes, making this skill invaluable in the civil services context.