The big question would be at what voltage? Most simple electronics want low voltage, but things like stoves and water heaters would want high voltage. To keep

The big question would be at what voltage? Most simple electronics want low voltage, but things like stoves and water heaters would want high voltage. To keep cable costs and resistive losses down, you'd want to keep the voltage as high as possible until just before it gets to the device. I doesn't generally make much sense to have one +5v power supply for a whole house, because that power would have to traverse a lot of cables before it gets where it's going. Historically, AC has been a lot easier to step up and down as needed, but maybe these days buck/boost converters are cheaper and just as good as a transformer. One advantage of DC is it doesn't have a "skin effect" where the current tends to just flow on the surface of the conductor. So, you can move more power over a solid DC cable than you can with AC at equivalent voltage. That might mean you can save on cabling costs with DC, but I don't know if it actually matters for household wiring.