If the connector was trying to provide 25 amps at 5 volts via the thin little wires, they would arc into gas almost immediately.
My phone charge does 5A at 5V without an issue, and my laptop doing 5A at 20V does so over tiny wires.
As an RV-er, I'm familar with both 12 volt and 120 volt systems. For a LED TV or other low wattage appliance, 12 volt is better, just because it directly comes from the batteries. However, for a load like a microwave, A/C, heater, or anything above 300 watts, trying to run that on 12 volts would require very fat, expensive cable.
You answer the question, then immediately forget the answer. You have AC at 240 (sigh, 110, if you must) and have outlets in some strategic areas (kitchens and for major appliances), and 12V or 48V everywhere else.
I think we should have a 48V internal wiring standard, with some 240V appliance plugs, for vacuums, refrigerators, washers and driers, and such. The dual-standard will complicate things slightly, but result in a large overall savings, as wall-warts are eliminated, and all their waste.
The term "for free" in the sense of "at no charge" is meaningless, confusing,
I've never seen anyone confused by it. Just the argumentative people on Slashdot
and manipulative
Ah, the real objection. It doesn't give a sufficiently evil connotation for those who hate the term.
Understanding is always the understanding of a smaller problem in relation to a bigger problem. -- P.D. Ouspensky