Bro, they don’t. The OS manages microphone access. If you allow it, yes, they may spy. But even then, the OS visible tells you via an icon that the microphone is used. It is the plain written truth, that we can not argue around. There has been a lot security research around this, stuff has been audited, Android is even open source, and no one has ever found even a hint of this being possible.

Echos and Google Homes are an entirely different story because they operate their microphones by design, their entire system works on always listening, and they don’t hide that.