Also, as I have written many times, Hong Kong's airspace is crimped by the mainland Chinese. Nothing has changed in the near 20 years since the new airport has been open. It doesn't matter how many runways they build at HKIA; one CB miles away shuts the joint down for hours. Each summer gets crazier and crazier. Even in good weather, delays are rife. Intelligent travellers are avoiding using HKG as a hub for connections.
Because of this and other factors, expansion will eventually stop, and CX and your career will be going nowhere.