Earlier quoted context omitted.
I used to be paranoid about companies using my microphone and camera to spy on me until I realized the data costs associated with the spying would be so great, that I'd notice. That single argument has ended my paranoia on the matter. I hope others can be at ease. That said, I still put tape on my laptop and refuse all tracking and ad requests.
They don’t have to send back all of the raw data, just analyses like ‘person X’s face detected, is in a noisy place’ or ‘conversation included these 5 keywords’. The processing and data transfer could also be deferred until the phone is idle or on WiFi.
Not without making a noticeable drain on the user's battery.