The issue with the e208 is efficiency based. Whether that is the motor, aerodynamic profile, tyres or something else I am unsure, but that’s why you get less range from that car. It’s nothing to do with the way that the car is charged. If you top it up with 20kWh of energy, it is the same 20kWh no matter if you put it in very slowly with a granny cable, or very quickly at a rapid charger, as @E7EV has explained above.
If you were to rapid charge your car multiple times a day, every single day it may cause problem over time and start to degrade the battery resulting in it being able to hold less capacity with a full charge, but I don’t think that is the point you are getting at here. Likewise, cell balancing is helpful with a full charge every now and then, helping you to get more out of the battery especially at the very top and bottom ends of the battery, but in day-to-day use, it really doesn’t matter how you charge your EV.
The simple fact is that some manufacturers take EVs more seriously than others. Some work hard to improve efficiency like Tesla, Hyundai, and to some extent Renault. Others like PSA, Jaguar, Audi and the recent offerings from Mercedes-Benz haven’t worked so hard on this side of things and you end up with less range per charge.
As for the charging speeds, the big thing that causes these differences is the voltage of the battery packs that each car has. That’s why the new Hyundai Ioniq charges so much slower than the old model for example. But the manufacturers also take into account how effective their cooling system is, and also trying to get the balance right between the convenience of faster charge speeds, and the risk of accelerated wear and degradation to the battery pack caused by the extra stress and heat that rapid charging can bring.