A better answer is three phase power. That reduces the size of inductors and capacitors needed in the DC converters while still letting you use a transformer to

A better answer is three phase power. That reduces the size of inductors and capacitors needed in the DC converters while still letting you use a transformer to drop from the highest acceptable line voltage (to minimize copper use/minimize losses) to whatever the device really wants. Bonus: Three phase transmits more power per "mass of copper" than single phase. Extra bonus: You will never have the stupid starting capacitor fail on any of your larger domestic motors!