[skrause]

Seeing the constructions makes me think that we're blessed in Germany for getting all three phases even in single apartments.

Here it's quote common (if no cheaper method of central hot water is available) to have on-demand water heaters like https://www.clage.com/de/produkte/durchlauferhitzer which usually have a maximum power output of 21 kW, so they aren't just used for showers, but can also fill up a bathtub quite quickly. They also don't hang inside the shower, but on any nearby wall.

They're connected to three-phase power with a 32A fuse on each phase.

[throwup238]

Those heaters are also popular in Russia, at least in Soviet-era buildings where the central water heater breaks frequently.