[aivisol]

That absolutely is. You could be better with 48 or even 24 volts, but then you are out of luck if you want to power a majority of devices which are 12v. So your only option is to go for USB-A wall socket which essentially is a wall-wart hidden in your wall. I do not see a good solution here.

[JoeAltmaier]

A buck convertor in the socket (cost: $1) with a voltage dial or selector would do the trick.