People make travel decisions based on the total travel time, which they weigh against cost. The table in your article just showed the “in-vehicle time”. A traveller is likely to consider the total time a journey takes, which includes time from home to airport (versus time to West Kowloon Terminus), time for check-in, time for the customs, immigration and quarantine (CIQ) formalities (in both point-of-origin and destination terminals), in-vehicle time (on plane or on train), and then the journey from the airport (or railway station) to the final destination.

Airlines typically expect passengers to arrive at the airport an hour-and-a-half to two hours before departure, and to be at the gate at least half an hour before departure.