Big appliances are already big, justifying putting an inverter on them if they can't be converted to DC. An inverter of appropriate size and power, of course, rather than a single mega one.

My argument is that this contest is a bandaid on an outdated way of thinking about power. Yes, safety is important. However, in your example we don't have to use physical-contact plugs. There are plenty of devices that can be powered or charged via induction.