The big plus about both Alexa and google assistant is that they are not restricted to any device (iOS and android) and will verbally give you an answer.
Alexa handles one command at a time and google assistant handles three commands at once.
Google Home works with a smaller number of smart home devices than Alexa.
On asking same questions to both, Google Assistant answered more questions correctly as compared to Alexa.
You can't set wake word to anything in google assistant just like in Alexa.
Google assistant has a better understanding of voice commands than Alexa.
It doesn't matter what you are using. Both google and Alexa are the future and they will keep on improving.