A daily driver does not become a bad car simply because its birthday keeps getting farther away. A well-maintained 15-year-old vehicle with reasonable mileage can make more sense than a neglected 8-year-old car with fewer miles.
That makes the odometer an imperfect judge of a car’s future. Mileage tells you how much the vehicle has traveled, but it cannot tell you how those miles happened, how the car was maintained, or which age-related parts may now need attention.