The Committee on Estimates is considered the largest committee of the Parliament due to its function and membership, which includes a wide representation of MPs from various parties and states. It plays a critical role in scrutinizing government expenditure and ensuring accountability, which aligns with the parliamentary oversight functions expected in a democratic system. This committee's significance is emphasized in standard reference materials as it is central to fiscal governance, reinforcing the importance of transparency and responsible financial management in public administration, crucial for UPSC aspirants to understand.