We have always had tools that can do each task well - INDIVIDUALLY. The value-add of these virtual assistants (and I presume we are talking about Siri, Google Now, and their breed) is that they are able to merge the different information together and help us manage the immediate tasks on hand.
If my morning commute is likely to be congested, it will warn me.
If it detects me lingering very near a wireless AP next to a box office, it can prompt me with some promotions to save a couple of bucks.
If I haven't contacted someone in my "VIP" list on their birthday, it can help me ensure that I stay in the good books.
But of course, it can also stab me in the back and send my data to hackers in Elbonia who will use my picture on "stop your balding" advertisements.
Excuse me while I go find an army of data werewolves on LinkedIn.