I mean, that's not really a fair comparison. EQC is more like the GLC, perhaps GLE at a stretch, and in Germany you'd usually get it with a 220d diesel, those get 40-50mpg easily.
The GLC 200d uses 5.2 L/100 km (best efficiency). Diesel is € 1.266/L. 5.2 * 1.266 = € 6.5832 / 100 km
So yea in DE it may be more cost beneficial to drive diesel than electric. If you get a GLC 300 using gasoline it goes up to € 9.798 / 100 km.
Germany is also densely populated, which means many can't charge at home and might need to pay a higher rate for electricity somewhere else.