Comment by tim333

There are some technical issues in moving beyond that. For example I was talking to a pilot in Africa and apparently for long haul between Europe and South Africa the local controller in the various countries en route were considered a bit useless go they had a particular frequency where they would occasionally say this if flight x over country y heading so and so direction and altitude and other planes on that frequency could here where they were - the radio range is ~200 miles. I'm not sure how you'd replace that other than with something like starlink which is quite recent.