The current ATC system is quite restrictive at busy airports, resulting in a lack of realism. As AI air traffic increases next year it will be very difficult to create a system that is as expeditious as live ATC, but I believe a few tweaks here and there can help to speed up the system. Landing clearance is currently given relatively early in the sim, normally at around 5nm final or when downwind. The runway is then blocked to departing aircraft. In reality when downwind calls are made the normal ATC response would be “C/S report final” If ATC landing clearances were then given at 2nm final, and the runway blocked then to departures, that would permit departing aircraft to be given clearance to "Line up and immediate take off " whenever an inbound aircraft is between 5nm or downwind and 2nm final. Immediate take off means not stopping on the runway after entry. So for the system to work there would be a responsibility attached to the departing pilot and there would need to be an ATC menu option to delay departure if the immediate take off criteria could not be met. Such is life.