Saving energy and resources by using three phase power

When electricity was first discovered there was a huge debate about whether AC or DC power was best, fortunately AC won out because DC switching would have been a huge problem and AC motors are cheaper.   But it evolved so that single phase was used almost exclusively in residential buildings although three phase is available on most power poles.  In the early days there was no air conditioning or heat pumps so with electricity used primarily for lighting there was no need for the extra expense of running two more wires to the building.  So that is how it evolved.

Three phase motors are smaller, use less copper, are more efficient, and are more reliable.  They do not require expensive start and run capacitors which are another source of failures.  They are widely used for heating and cooling in buildings where three phase power is available.  Since most residential buildings power usage is mostly the heating and cooling it should be mandatory that new or remodeled (where justifiable) buildings spend the relatively minor money to run the two (or three, delta or Y) extra wires necessary to install energy saving three phase.  Three phase motors are readily available for Heating/AC units and could be for larger appliances.

This switchover would have to start with code enforcement first suggesting it and then making it part of the building code where it is practical, in new housing projects, etc.

I am no expert on any of this and there are probably experts that could add a lot to my suggestions.  There could also be a fly in the ointment that makes the idea impractical but to me it seems like a way to save our dwindling resources and energy while saving money.

I would welcome any ideas or information about implementing any of this.