Aren't all of the gauges from speed, temperature, tach, fuel, etc. meant to show engineering ranges and not optimal ranges? If you designed a car that couldn't

Aren't all of the gauges from speed, temperature, tach, fuel, etc. meant to show engineering ranges and not optimal ranges? If you designed a car that couldn't go faster than 100KMh, I assume driving it 100% of the time at 100kmh would be more detrimental to the car's longevity than operating a more capable car at a lower percentage of its capability. I realize I'm making some assumptions here, but maybe the maximum speed of a car is an design artifact of maximizing for multiple variables (longevity, fuel consumption, maintenance costs), not just speed. I'm not an engineer so I have no idea what I'm talking about.