Simply the less standing around and waiting twiddling thumbs the better. If you board first you can settle in put feet up and have a glass of champagne. Better than sitting in departures area. And you don’t have to queue in the often hot and cramped ramp tunnel to board.

Short haul it’s the same plus overhead locker space.

Exactly why it shouldn’t be a group but a short cut boarding at any time to make it all efficient. CK have reps to help I think sometimes and can even escort all the way to the seat so no tunnel issues.