My experience with electronic LED and CFL ballasts and electronically commutated motors have been all bad.
For instance the EPA now requires refrigerators to use electronically commutated motors in place of the shaded pole motors for the evaporator in refrigerators. These motors cost 10 times more, and fail because of their sensitivity to power quality. The shaded pole motors they replaced lasted decades.
So what was more wasteful? I have to replace the evaporator motor in my refrigerator about every 2 years, at a cost of $30 plus my time. Do you think a shaded pole motor, which will never fail, draws $30 worth of power over 2 years? Of course not. It is not even close.
LED and CFL bulbs with electronics ballasts have the same problem. The operating life specifications of LED bulbs are bullshit based only on the operating life of the LEDs, when the electronic ballast is what will fail, either due to poor power quality or high temperatures, often in months.
DC power is not going to make that any better. You might claim that ubiquitous DC to DC conversion will result in better power quality, but now it will also be the ubiquitous and expensive DC to DC converters which fail. As a bonus, they will spew out RFI.