Comfort and Convenience
Preferred seating height is a common example: some people want a raised, commanding view over the bonnet, while others sit low for a more enclosed feel. Body proportions and long habit shape which position feels natural.
Safety and Driver Assistance
Spending a few minutes with wipers, lights, mirrors and hazard switches while parked means those actions are already familiar later, and nothing has to be worked out in the middle of a journey.
Multimedia and Connectivity
Keeping a phone charged during long drives is a separate matter from playing music or taking calls; if a car offers a charging point, it is worth checking that it suits your cable and preferred phone position.