There’s an old joke about the cockpit of the future, which is so highly-automated as to comprise of a pilot and a dog; the dog was there to bit e the pilot if they tried to touch the controls!
Re-framing this joke, might the air traffic controller position of the future be a staffed by controller and a dog? This time the dog is trained to bite if the controller tries to offer a ‘direct’.
Why?
‘Directs’ look like short cuts to controllers and pilots (who may request them), but they may be directs into a headwind, burning more fuel. Asking for and giving a direct assumes that the controller or pilot know better than the airline’s flight plan, which is based on predicted winds and minimum costs (fuel etc.)
As airlines increasingly invest in advanced flight planning systems, we should consider that the flight planned route is likely the best and there is no advantage in a direct.
There are some caveats to this:
(a) The airline may not have submitted an optimum flight plan, either due to their system or how they resource it.
(b) An airspace reservation (special use airspace) may have been deactivated (you would have to imagine some pretty strong winds to think that a direct would not be beneficial in this case). A caveat to this caveat is that where the destination is likely to have airborne holding for the arrivals stream.
(c) The pilots have updated forecast winds sent to their Electronic Flight Bag (EFB).
Image ChatGPT, not a real ACC.
