Better is probably a poor word, but consistent at least. Even good drivers may run the speed limit and be "perfectly safe", but the autopilot will always stay at the speed limit and will always make the same choices in a given situation - there's no emotion or influence (alcohol, drugs, bad mood, etc.). In short, they are boring but safe.
I agree. It's like arguing that autonomous weapons systems are better than human-operated because they don't get tired, whilst neglecting to mention that, say, their object detection algorithms can't tell the difference between combatants and civilians.
Autonomous systems, as a technology, are capable of performing better than humans; that doesn't imply that some particular autonomous system (e.g. Tesla's Autopilot) does so right now.
