Hey,
In the real world, Low-Cost Carriers like Ryanair don’t just fly where the demand is, but they create it.(Induced Demand) By offering low fares and consistent service to previously “unknown” or secondary destinations, they make travel viable for people who wouldn’t have flown otherwise.
They way I understand the game there is currently no way of doing that, limiting playstyles and viable airports.
Instead of static demand it would be great for demand to change over time by offering regular service and offering low fares. You could add “multipliers” for tourist destinations (like being close to the sea, warm temperatures), which would accelerate the growth of demand. Another “multiplier” could be proximity to cities, which could make some secondary airports or airports like Frankfurt Hahn or Memmingen more viable.
By expanding the “Building” section of the game there could be things to boost growth additionally. like Shuttle Bus Services (to close cities) or hotels.
Introducing a “Growth Factor” would allow for more diverse business strategies. It would reward players for developing niche markets and secondary bases, rather than everyone just fighting over the same high-density hubs.