“…automation doesn’t talk on the radio.”
Perhaps inadvertently (?), you’ve hit a nail upon its head.
If you set out to AUTOMATE an air traffic control system, why on Earth would you utilize a century-old paradigm of open-frequency verbal communications?
It’s the equivalent of trying to improve carbon paper - at a cost of (endless) billions of dollars.
Old YARSism: “The very best implementation of a flawed concept is, itself, fatally flawed.”