So that 380V would be for 3 phase to a home which is not always the case. There are plenty of homes in Europe that only have single phase to the house which is at 230V.
So how would you run an instant water heater or electric induction stove then? Every apartment and house I've ever lived in had 380V three-phase right to the kitchen, to the bathroom, and to basement rooms (e.g. for prosumer workshop tools).
We don't run an instant water heater. It's all gas or electric boilers.
For the stove I wired one phase to all the burners and the oven. It had one, two or three phase options. They're on a separate circuit with a 16 amp fuse. It's 2200W I believe. The breaker has never tripped.
400V is just not very common for residential in the Eastern Europe, maybe in your country you have instant electric heaters and other powerful appliances. My dad has recently upgraded his house to 400V 3 phase though, although he didn't need it but it's nice to have.
> So how would you run an instant water heater or electric induction stove then? Every apartment and house I've ever lived in had 380V three-phase right to the kitchen,
I run an induction stove on 220V single phase every day here in the US.