We DO have self driving cars. They just can’t handle every possible circumstance. To be fair, neither can most human drivers. They can and do drive with human drivers, and the makers try to push that they are safer than humans. But, if they push too hard, then someone besides me will argue that they should be on the hook for liability if their AI is driving, and they do not want that. Thus you get the “it helps, but you should still be driving,” nonsense.
I did not address pricing because it is the least important thing you brought up. If the apps make it a ‘must have,’ item, there will be affordable versions that people will get. Not everyone has a 13 pro max, but almost everyone has a smart phone.