With automation taking over more and more of the task of " flying" the aeroplane, the task of pilots is becoming increasingly one of simply monitoring - which humans are not particularly good at, they get bored and distracted very easily.
By giving a running commentary of what the automatics are doing, it is hoped that this will ensure that at least one of the pilots is paying attention and will spot any irregularity.
Believe me, it's gonna get a lot worse !