Why do we use current sources as load in differential amplifiers?

Current sources are used as loads in differential amplifiers to improve their performance by providing high output impedance, which enhances the gain of the amplifier. They also help in maintaining a constant current through the differential pair, ensuring better linearity and increased common-mode rejection ratio (CMRR). This results in improved signal integrity and noise immunity, making differential amplifiers more effective for applications requiring precise signal amplification.