Smart speakers are designed to listen, obviously! Streaming audio is not seen as suspicious. Also they aren not phones and not using wifi, not LTE/4G uplinks,

Smart speakers are designed to listen, obviously! Streaming audio is not seen as suspicious. Also they aren not phones and not using wifi, not LTE/4G uplinks, making it more easy to stream audio without hitting bandwidth caps or using too much battery. It's way much easier to notice if a phone streams audio often and unnecessarily.