I was thinking of a similar possible problem during my commute this morning, not with automated driving but with automatic equipment and systems in general. Does convenience breed mental laziness and/or decay? In our increasingly automated and comfortable existence, what experiences confront us with the need for high focus and alertness, or systematic problem solving? (Speaking of humans in general, not just engineers and other professionals who benefit from this kind of activity in their work.) So many things have been reduced (usually delightfully so) to point, click and enjoy.
Some physical environments for advanced age folks are designed with features to promote extra physical exertion, to help maintain the occupants' fitness, which in turn promotes safety. (Better balance, fewer falls.)
Similarly, we might consider building-in a baseline requirement of mental activity for the operation of certain systems. In the short term, this might increase alertness in the moment, as in the semi-autonomous driving example. (In that case, perhaps a UI that requires maintaining a certain amount of eye motion across the road, or particular posture.) In the long term, perhaps other (more challenging?) in-built exercises will promote mental and neurological health in people whose work and play would otherwise fail to be stimulating.