The phone app misses lots of data the car can collent and send. When, how frequently, and how long turn indicators are used. How aggressively the throttle and brake are applied, how frequently pre-tensioners and other safety features activate, how closely the radar or lidar-equipped cruise control sees you following others, and I'm sure lots I haven't thought of

Been asked that before—don’t always use one. Insurers will have to buy that data from the telecom if my phone’s on.

Not sure how common it is for Verizon, AT&T, Google (Maps), Apple (Maps) to sell to insurers (or brokers who insurers use). Perhaps pretty common? I’m sure they often can deanonymize it if they do.