Why might a pilot be required to perform an emergency descent?

A pilot might be required to perform an emergency descent primarily to reduce altitude swiftly for safety reasons. This maneuver is often necessary in situations where there is a rapid decompression, smoke or fire in the aircraft, or other emergencies that may pose an immediate threat to the health and safety of the passengers and crew. By descending quickly to a lower altitude, the pilot can often move to a breathable air environment, avoid dangerous conditions, or prepare for a landing at a safer elevation.

The primary focus of an emergency descent is to maintain safety and ensure that the aircraft can be controlled and landed as quickly and safely as possible. While other aspects, such as fuel efficiency or return times, might be considerations in a different context, they do not take precedence during an emergency descent which prioritizes the immediate well-being of everyone on board.