That depends on where you live. Here in the UK, a transformer normally powers a whole block of houses or more. Most wiring in the street is 400V/230VAC.
That is true, the wiring from the local substation to houses is three phase 415/240 V, with phases alternating between houses to balance the load. Even so, there is very likely an 11 kV feeder running under many streets to supply the substations.
When these subsurface 11 kV feeders get old and fail they create a very exciting bang under the pavement (sidewalk) that can cause passing pedestrians to jump out of their skins