Why does Allah appoint angels to carry out tasks instead of doing them Himself?

Belief in angels and their functions is part of faith, for they manage the affairs of the universe by Allah's permission and command. They do nothing but what they are commanded to do. Allah Almighty creates with profound wisdom, which we may or may not comprehend.

The creation of angels demonstrates the perfection of Allah's Lordship and Divinity, deepens fear and awe of Him, and increases love and hope in Him.

This highlights Allah's greatness and power, and His care for humanity through entrusting angels with their protection and the recording of their deeds, which signifies the perfection of order and precision in the universe.