Cornering the market on every route and filling up the order book on Day 1 is literally impossible considering airlines only start with $7.5-100 million depending on the world.
Sandbox worlds are meant to be super short, the 5 minute time seems to work out well to allow them to constantly reset. Realistic worlds being realtime would alter the gameplay too significantly in a way I believe most players would dislike.
A "market study" or similar feature would just be a bit time-consuming and impede the ability of players to make routes easily.
You may call it impossible, but that's the routemap I saw when I looked at Cathay Pacific. Calling me a liar does not change what I saw.