Earlier quoted context omitted.
Amazon might have been the first to launch a dedicated device that can do voice search but Google was doing it(on Android) before such a device was launched by amazon.
Right, but were their efforts successful? That's the main difference here, bringing a new product to market successfully . Long before voice assistants/search became a thing with smart phones there was Google 411 ... which no one remembers. https://en.wikipedia.org/wiki/GOOG-411
I'd guess that 20% of Google's mobile queries in 2016 are a few orders of magnitude larger than Amazon's total voice search queries, effectively making Amazon's voice queries a drop in the ocean.