Comfort and Convenience
Cabin temperature is rarely agreed on. Body size, clothing and where someone sits relative to vents and glass all change how warm a space feels, so the setting that suits the driver may not suit a passenger.
Safety and Driver Assistance
Setting mirrors, seat and lights before pulling away takes a moment and avoids fiddling once passengers are aboard and conversation starts. Doing it while parked also means checking that everyone is settled before the journey begins.
Multimedia and Connectivity
Passengers often arrive with a low battery, so a power source they can reach matters on longer trips. Where charging is available, it is a separate question from taking calls or playing music, each handled in its own way.