Have I missed something?
Why the smaller Cabin Bag?
Those of us that travel regularly between airports have spent many years getting what we NEED for overnight stops into a Flight Case, or similar, to enable carrying a bag without waiting at Baggage Carousels.
(Now reduced to a change of clothes, elect shaver and toothbrush, plus optional PC, notebooks, etc.)
This new size doesn't allow the carriage of much more than a wallet!