Earlier quoted context omitted.
To collect data so they can do marketing and advertising to customers.
How does that work here? Say I have that toothbrush, the app, and say I had to sign up to use it. What they know is how long the toothbrush is on. How are they going to monetize that data?
You get permissions to whatever you ask for. The unsavvy user will click yes.
You get a push notification channel that can interrupt the user ANY time of day or night and get their immediate attention. Suggesting products and "deals".
Use your imagination. Think like an asshole.