The usefulness of this information is a common misconception. Without data on the surrounding cars, there is no context and the numbers are meaningless. Maybe if the driver is going over 100mph, that is valid but most the data is meaningless. Braking to avoid an animal, pedestrian or road defect isn't the same as random recklessness. Context. Average smartphone gps accuracy on a quick google says 16ft, often well within the distance between a highway and the parallel side road.
This is assuming the owner is doing the data gathering (as in rentals), I'm not even touching the spying aspect of it if it is your car. That is inexcusable. The car makers should make this data gathering more controllable and the insurance companies should be opt-in if some misguided person wants this surveillance.