This is nothing new, but so many folks dont seem to know anything about it. It isnt hard to disable mic use by apps, and it really helps your phone run better to not have them running in the background, while conserving power and data.

https://www.wired.com/2017/05/hundreds-apps-can-listen-beacons-cant-hear/

If you have an Alexa or Google device listening all the time, I dont know how to help you, unless it is a version you can set up that only listens when you press an activation button of some sort.