Mock tests provide candidates with a simulated experience of the UPSC Civil Services Exam, helping them understand the exam pattern, time management, and question difficulty. They allow for self-assessment, letting candidates evaluate their preparation levels and identify weak areas requiring further study. Additionally, mock tests help build exam temperament, which is crucial on the day of the actual examination. Regularly attempting these tests fosters confidence and prepares candidates for the real exam environment, aiding in effective performance.