The last two sentences seem contradictory. If the system cannot detect by itself when it is safe to be used, the driver will as well have to react when it becomes unsafe to use?
It means the system is constructed such that it won't get into a situation it can not handle. But it does not handle any random situation a human can put it in.
You're right, it should probably be a bit more muted. Perhaps "When enabled, [significantly less] driver attention is required." The driver can't go to sleep, for example, lest they miss the alert that indicates "oh no I can't figure it out anymore." Though the car would likely be designed to timeout on driver response and execute a safe deceleration/pull-aside maneuver.
