Isn't thinking far enough. As I've outlined elsewhere, we are well into the realm where we can make our plugs much smarter than that. In most cases to the point that they can negotiate, with a data protocol, what type of power is available and is needed, and for devices that are older or too cheap to have even a cheap power negotiation circuit, use the resistor system that today's universal laptop power supplies use.

Ie. the power supply puts a small voltage on pin 3. This either powers a chip that does a data protocol to negotiate power, or it's just a resistor, in which case it measures the resistance(s) and calculates what power to send. An alternate system (for dumb power supply and smart device) has full power come on the main power pins (which the device can easily measure) and the voltage on pin 3 tells how much current you can take from the supply. For dumb supply and dumb device, we're back to what we have here. Cheap adapters would allow dumb devices or supplies to connect to the smart system.

As for DC to the house, this has been proposed, but to make it work you would need to have big inverters for all the legacy devices. These are now getting cheap enough. But the switchover is hard. I think it would begin with a smart power system, and wiring a house with mostly DC plugs and a few AC ones, with a big DC power supply back at the breaker box.

I have also seen talk of DC for long haul, since conversion of DC is now more possible.