Humans have been making mistakes with every new assistive technology. When ABS was optional, people with ABS cars would pump the brakes and end up not stopping in time. With cruise control, there are urban legends of RV drivers going back to make a sandwich.

Eventually people figure this stuff out, but as was discussed in other Tesla threads, there is a risk of entering an uncanny valley where it's actually more dangerous to have the assistive tech in an emergency, but safer in non-emergencies.