> That ATC still takes place over radio just seems insane at this point.
Voice communication is insane? I suspect you are ignorant of what it is like to actually fly a large aircraft into a busy airport. Fault-tolerant and highly available hardware must facilitate low-latency, single-threaded communication with high semantic density in order to achieve multi-dimensional consensus in a safety-critical, heterogeneous, adversarial environment.
Voice communication has the advantage is that it can be used without taking off hands and attention off controls. Digital solution would require using device.
Voice communication can still be used for anything out of the ordinary despite automating the common case.
Almost all voice transmissions are routine instructions/clearances from ground to air, with the pilots reading them back to reduce the chance of errors. In fact, this already exists and is in wide use in (at least) the US, EU, and in transoceanic airspace.
Of course, now you have two systems that can fail, and reducing reliance on the older one can easily cause automation complacency (which is a well-researched source of errors) and require more frequent refresher courses if the skill is not practiced on a continuos basis.
I suspect that that these are the reasons it's not commonly used for approach and tower operations: There's a lot more spontaneous and/or nonstandard stuff happening in those flight phases, and as you say you don't want a pilot's eyes on a tiny screen/keyboard instead of on their instruments or out the window.
I was originally going to reply with "Try moving a couch with eye blinks and hand signals" and then decided against it. Pilots have enough to do with their hands and feet as it is and looking for and mashing a "I accept the terms and conditions of the landing clearance" button is not really in line with the task at hand.
Listening to some recent close call ATC tapes, yes, it seems absolutely insane to manage current traffic levels with the existing number of controllers over voice.
I don't doubt that it's a very safe system with enough slack allowing for intentional redundancy. But as it is, some of these controllers seem to be limited by their ability to pronounce instructions, leaving absolutely no margin for error and presumably very little room for conscious thought.
Voice communication is insane? I suspect you are ignorant of what it is like to actually fly a large aircraft into a busy airport. Fault-tolerant and highly available hardware must facilitate low-latency, single-threaded communication with high semantic density in order to achieve multi-dimensional consensus in a safety-critical, heterogeneous, adversarial environment.
There is some interesting research that captures this sentiment and shows how complex a solution might need to be (replace "faulty agent" with "human error"): https://www.sciencedirect.com/science/article/abs/pii/S00051...