They recognize much more objects on the road but major problem is to do not cause a lot of false alarms. e.g. You don't really want to drive car which decided that plastic bag on the highway is reason for emergency braking, on the other hand is that really plastic bag or some drunk person who is sleeping on the road...

I remember when Volvo introduced IntelliSafe technology few years ago that car was totally "paranoid" and it was beeping all the time -> most of drivers deactivated that system.