You need less workers to track other workers. Instead you have devices that you pay for one time instead of a salary in theory. I'd guess the bean counters have looked at it and figured it saves money in salary and also in other ways.

I know that UPS was (and I assume still is but I have not l been with the company in about 15 years) big into telematics. I remember one of their biggest safety concerns was backing and they knew how many times you did it and if you did it before or after you parked. If you backed over a certain amount of times per day or if you did it once after parking and turning off your package car, you'd be in with management being questioned about it.