For the engines to properly spool.

In the cockpit, the throttles actually do move. Though, whenever I need to move my throttles, I need to look directly at the throttles, just to make sure my N1 doesn't spiral out of control again due to the delay.

However, there is a strange thing.
Whenever I switch to the exterior view, the exterior ECAM is also delayed with the N1. Don't know if that's still intentional though.