Nowadays you can listen to ATC from nearly anywhere by visiting https://liveatc.net/
...and I can't understand hardly a word they say. Even having a slight idea of the phraseology from countless hours in MSFS and watching VATSIM streams on Twitch, when it comes to the real thing, they talk so fast and there's so much static that it blows my mind that anybody can understand them at all.
Controller cadence is a bit geographical - the busier the airspace the faster the tempo, and the more important it is to speak up.
AM simplex radio works amazingly well overall for this purpose, and none of the potential technology that could replace it would be as safe or reliable..
Like, sure, in the military there's the ability to do various and sundry things to secure your comms and navigation which are not worth discussing here. But in the civilian world, there's largely no reason to go to the trouble and expense.