Google Assistant queries are still reviewed and transcribed by humans
According to a report by VRT NWS, 0.2 percent of all queries submitted to Google Assistant by users worldwide are recorded and analyzed. In one noted case, the address and personal familial information of a user was a clear part of the recording.
According to a response released by Google via its official blog, the case highlighted by VRT NWS was in violation of the company's data security policies, with an internal investigation currently ongoing. The blog post goes on to say that all recordings sent to Google have no association with the user accounts from where the recordings originate. Those tasked with reviewing the recordings are also "directed" not to transcribe any audio information outside of those directly addressed to Google, such as background conversations.
This incident is one of many that calls into question the privacy and integrity of automated personal assistants such as Google Assistant and Amazon Alexa. That said, as with all of Apple's products, despite being exclusive to its hardware, Siri does not collect or send any personal data to the company. Despite this, it's understandable why you may not want to utilize any of these voice services considering the many horror stories that circulate in the news cycle concerning them.