For a long while that was the primary reason we didnt have them.
No ATC and untrained mentally unstable drivers were said to need self flying cars that would all be AI controlled.
Put in or speak destination and after it connected and got the route it would fly you to your destination and land itself.
Not that I liked that version.
In the 70s Moeller promised me a flying car that had more of a Battlestar Gallactica Viper fighter look, Id prefer that one.