Because a lot of the exageration can be attributed to weather. You are going to have shorter range in the winter.
I don’t really buy that. We don’t (well, most people don’t) drive around in freezing cold cars. The cares are heated and it doesn’t use much energy. Also if your EV is plugged in overnight it should be pre-heated to a sensible temperature (still cold, but not freezing).
Combustion engines also struggle in cold weather - that’s why the cooling system is disconnected until the engine reaches operating temperature. Electric motors and batteries generate heat when they’re running - harnessing that to keep the batteries warm.
Some brands only lose 3% of their range in cold weather. The shitty brands lose up to 35%… that’s not the technology’s fault, it’s a failure by the engineering team and consumers should be entitled to a refund if it was sold in a cold climate with only the summer range advertised. The car isn’t fit for purpose.