Yeah, a primitive autopilot in a plane just needs an altimeter and compass, but a AoA sensor, speedometer, fuel level sensor, and pitch sensor help to detect unsafe conditions like runaway pitch, stalling, overspeed, low fuel, etc. Each of those sensors is providing a simple 1-dimensional data point. Redundancy is relatively inexpensive.

Automatic lane keeping in a car requires cameras that software needs to then analyze to find the lines in the road in real time. But if you want a "set it and read a book for an hour", then you have to respond to other traffic. No longer just some simple PID controllers, the software now needs to plan and execute based on surrounding traffic.