Google's Assistant technology and feature are already available to some degree through the use of the Allo app, and they'll be available in more robust forms in the Google Home speaker and Pixel phones that are shipping later this month. Even in it's early form, though, Google Assistant already has an edge on Amazon's Alexa software for a few key reasons. One of those is the ability to kick back results to what seem like rather basic questions, such as asking the travel time between two particular places. Because Google Assistant has a bevy of information and data at its fingertips, including location information thanks to being tied to a Google account, it can feed answers like travel times between locations back to a user with relative ease. Amazon's Alexa, not so much, it would seem.
This doesn't mean that Alexa is inferior, at least not as a whole, as there are more than a few things that the Echo speaker can do that Google Assistant can not, such as power on your Tesla Model S and pull it out of the driveway. Nevertheless, Google Assistant still has an edge on Alexa and a main reason for that is that Google has built Assistant to have the ability to deliver contextualized responses. You can have a conversation with it that flows somewhat naturally in a similar manner you might have a conversation with a friend or family member. This is where there lies a big difference between Assistant and Alexa.
Having said that, Amazon is continually building on new skills for the Alexa software that powers the Echo speaker, and because of its open nature it seems to be adding new ones quite consistently and at a rather fast pace thanks to the help of the development community. There's also a good chance that Amazon could catch up to Google with the contextualization as Amazon is constantly improving their software, tweaking things to get them just right, adding on new bits and introducing new features. Amazon has bet big on A.I. and there's no reason for them to slow down and keep the Alexa software to simply being able to do things for you like place an order for pizza or turn off the lights. To some degree you can even think of both pieces of technology as meant for different means. If you want something that is capable of interacting with tons of various smart home items, and completing arbitrary tasks for you in a manner that is quite clearly being handled by an A.I bot, then Alexa should be able to serve your needs, and quite well. If you want something that is capable of interacting with a few smart home items and having a normal sounding conversation with you that flows almost as naturally as it does with another human being, then Google Assistant might be a better fit. When it comes down to it, both products have their niche, and both are undoubtedly going to continue expanding. So Google Assistant is smarter than Alexa, as it can give you more information, but Alexa still has plenty of skills too and is a huge benefit in its own right.