Because there are Range Rovers to challenge.
Without question Audi has huge confidence in its ever growing SUV lineup. Earlier this month the Q8 flagship SUV was unveiled, but apparently there's room for something one number higher. According to Autocar, Audi is intent to launch a Q9 for the specific purpose of taking on the likes of the Range Rover. It will, however, be slotted below the Bentley Bentayga in terms of all-out luxury and price. Think of it like this: the Q8 directly rivals the Range Rover Sport while the Q9 will compete with the Range Rover models.
The Q9's development will also not impact the upcoming Q8 plug-in hybrid and RS What will the Q9 look like? Obviously it'll bear a strong resemblance to the Q8, but Audi chief designer Marc Lichte told Autocar he and his team "have so many ideas, so many ideas…" Point being, Audi could use the Q9 to either further its latest design language or use it as the starting point of something new entirely. During our conversations with Lichte he told us about his desire to give individual models their own unique looks instead of the so-called "Russian doll" trend Audi had been doing for years. Audi has yet to officially announce the Q9 project, but that likely won't happen until after Q8 sales get underway.
There's also another factor that'll potentially slow down the Q9's progress: Audi CEO Rupert Stadler is currently sitting in jail for his alleged role in the pre-Dieselgate cover-up. The reveal of the Audi e-tron has also been delayed due to Stadler's absence. In the meantime, Audi will be paying attention to initial Q8 feedback and apply that and more to the Q9, which could arrive around 2021.