I suspect that wasn't always so. There's no one standard gasoline and yet we figured out how to make that work. It's a common sight to see filling stations with three grades of gasoline and at least one grade of diesel fuel. Diesel and gasoline nozzles are apparently different. I read somewhere that ethanol filling nozzles are different. If we can manage to have these different fuels and nozzles then we can manage different chargers.
One solution I expect to be popular is having two power inlets on the car. One is the "standard" (or however close we can get to such a thing), and the other being the manufacturer preferred power inlet. It sounds like the CCS connector can handle 50 kW while Tesla's connector can handle 250 kW. If I were a Tesla owner and the government dictated I had to use the 50 kW charger away from home then I'd be a bit pissed. It's when away from home I need that fastest charge.
I don't think manufacturers will be shipping cars with two different inlets unless they really have to, I base this on the fact that Tesla is already equipping their cars with *only* CCS in Europe. BTW CCS is capable of 350 kW charging not 50 so there is no downside at all to the EU mandating this standard...
Reactor error - core dumped!