And yet, isn't air travel safer than ever, in part because of sophisticated in-flight autopilot systems?
I don't know why airline travel is so safe. If I may speculate, air travel is safe because of aggressive regulation, which mandates extreme maintenance levels, lots of pilot (re)training, checklists, pilot freshness requirements, the ability to land in poor visibility (via instruments only), and strong accident analysis. And, yes, finally, technology has been able to remove some sources of human error.
And yet, the crash of Air France 447, which killed 228 passengers, was caused by a pilot's poor reaction to the unexpected disengagement of the autopilot. Similarly, Asiana Airlines Flight 214. In response the FAA has recommended pilots spend (slightly) less time using autopilot.
I think that until planes, or cars, can operate completely autonomously, automation will reduce the most common accidents yet make the worst accidents worse, by reducing the skill level of humans to respond to failures in automation.
As an example, look at Tesla's fatality rate. As best I can tell, it's one death per two billion miles driven without Autopilot (this excludes suicides and car chases) and one per 130 million miles with it enabled. It's 15x better without Autopilot.
In my own experience, I find that AP reduces my awareness of whether my blind spots are clear. I just can't help it.
None of this should detract from Tesla's achievements. I use AP all the time, especially when I need to use the touchscreen, which is patently unsafe to do otherwise. And eventually it will prevent more fatalities than human driving. Onwards!