The very same thing is true with fuel economy ratings. The usefulness in such statistics is not in their specific accuracy for one vehicle, but in comparing more than one vehicle with each other (provided, of course, that the procedure for arriving at the ratings are similar enough).
But that’s exactly why it’s a bad unit to make comparisons on…I could claim 500km of range* in 15 on a car that only has 50kW of charging speed.
*but only if you keep the speed under 50km/h, the temperature is 25°C, the road is dry and there is a tail wind.
By using km as the unit, they can obfuscate a ton of information that make direct comparisons nearly impossible.
The very same thing is true with fuel economy ratings. The usefulness in such statistics is not in their specific accuracy for one vehicle, but in comparing more than one vehicle with each other (provided, of course, that the procedure for arriving at the ratings are similar enough).