Comfort and Convenience
Cabin temperature is a matter of taste rather than a single correct number. Metabolism, clothing and whether someone has just walked to the car all change what feels pleasant on the same morning.
Safety and Driver Assistance
Familiarity with controls is easiest to build while parked, with time to look. Anyone borrowing a car, or returning to one after a long gap, benefits from that unhurried few minutes.
Multimedia and Connectivity
Calls taken in traffic are the ones most likely to be misheard. Where hands-free telephony is set up, its everyday worth lies in keeping the conversation audible without the phone leaving its place.