You need to understand how our system works. The 3-phase lines atop our poles are generally 13 - 15 kV in residential or semi-rural areas. In industrial districts, they will commonly run three lines to transformers, dropping each to 277 volts to ground, which gives you 480 volts between phases (delta configuration). In "light commercial" districts, they'll do the same but to 208 volt (Y-configuration, with neutral), which gives you a convenient 120V to ground.
But in residential districts, it really makes no sense to add the enormous cost of three transformers for each house or grouping of houses, rather they pull just one phase to a single-phase transformer, for each group of several houses. As you move down the road, they alternate the phase to which they're attaching each local transformer, so the load stays roughly balanced back to the substation.
None of this is by accident or happenstance, it is a highly-optimized system, that has developed over many decades. Those thinking they have some more efficient answer are usually just ignorant of all of the costs involved, with regard to installation, transmission efficiency, and repair or maintenance costs.
As to "most of the western world", are you implying that most other countries run 3-phase power directly into residential buildings? I suppose it's possible, but I wasn't aware of that.
