Not Understanding Google Now
Kelly writes, "... Cortana could tell its user when to depart for the airport after reading an email containing flight information ... It would automatically check the flight status and traffic conditions for the commute. ... Such advancement indicates a level of artificial intelligence that Apple and Google have not yet demonstrated."
It's clear to me that you have not used or activated Google Now on your device. Google has been doing everything you mention for at least a year, or more. If a flight is delayed or there is heavy traffic on the way to the airport, Google lets me know. Google's Now cards are incredibly prescient, at least in my use. I have had cards start appearing telling me commute times to places that are not indicated in my Calendar events, simply because I typically travel to those places at particular times. It's incredibly good at finding potential Calendar events in Gmail messages. It presents relevant articles for me to read, based on sites I've visited before, and lets me know of new content for sites I regularly visit. It reminds me of birthdays and can easily be told to remind me of anything else I want it to.
I find all of that functionality incredibly useful and beneficial to my daily life. For full disclosure, I haven't ever used Siri or Cortana, so I'm not trying to compare the two, I'm just saying I think Google Now can do more than you realize.