Comfort and Convenience
Fresh air is not a shared taste: during a wait at the sports ground, one person may want a window cracked open, while another prefers it closed so talk stays inside.
Safety and Driver Assistance
Before a supermarket run, it helps to know which control opens the boot and which one works the windows, so you are not guessing at the kerb.
Multimedia and Connectivity
Children who want a story recording on the way to a sports club can pause or skip tracks if those controls exist, which keeps playback usable during the journey.