I’d just like to build on @Alphadog4646’s statement here. Our most experienced IFATC controllers can send commands in a second, if not less. Most people can barely speak a single word in that time. Now imagine having to speak out loud, using proper terminology. Considerably slower, right?
But wait. There’s more. Now consider it’s a super busy airspace like at EGLL, or during an FNF. You’re going to have about 10-15 planes on the ground and almost double that amount in the air, all needing commands to vector them towards final approach or clearance to taxi to a runway. That’s a lot of words, and a lot of time, being taken up by everybody speaking their commands. The poor controller, in turn, has to respond to each and every one of those commands, while still speaking out loud and using precise terminology. Factor in the time it takes to convert our speech into a mechanical voice, and you get an unbearable session for controllers and pilots alike.
It’s a good idea, in theory, and it could indeed increase the realism of the game. However, with the kind of traffic that any one airport could receive here in IF, speaking out loud would just cause more problems and ultimately fail. Don’t get me wrong, I think this is pretty cool, but the way I see it, it’s just not practical for our purposes.