I don’t think it would come as a surprise to anyone that Google uses audio recordings of the things we say to the Google Assistant on our phones and Google’s smart speakers. After all, data collection is one of the many ways that Google not only earns money, but also trains its AI, making its services better over time to get us to use them even more and give Google more data. It’s a vicious circle.
So if you’re using a Google Home smart speaker, or a Nest Hub, maybe stop and think whether the utility it’s offering you is enough to let random strangers listen in on things you’re saying to the Assistant, and also, sometimes, thing you’re saying when the Assistant accidentally activates.