There are people that wire up their entire homes with Anderson Powerpoles for DC everywhere. There's also PoE. The non-nerd's option is 12V cigarette lighter plugs, 5V USB-A plugs or USB-C. Hackaday had an article on this topic a while back: https://hackaday.com/2016/12/21/so-wheres-my-low-voltage-dc-...
I lived on a boat for a while and I used almost exclusively DC - it worked out pretty well. I used hard wiring and cigarette lighter plugs and that worked fine. The problem with wiring a house is that DC losses start to be huge over decent distances (100+ feet starts to be really tough.) I feel like that's one reason why DC is only really standard on cars/boats/motorhomes.
USB Power Delivery 3.1 specifies power over USB-C up to 5A @ 48V. 240W doesn't give you a very powerful desktop: probably an SSD, a 65W CPU and a low power GPU. But that's still a decent desktop.
I don't necessarily think it's wise to do 5 amps over USB-C, but it is a standardized DC outlet. Personally, USB-A is still a more useful power outlet, but nobody is insane enough to shove 240W over it.
Yes, USC-C with PD is the winning idea for DC infrastructure. All new homes should come with PD outlets. The outlets could be fed with 12 gauge copper and the PD electronics should be built in to the individual outlets.
Low-voltage DC for long wire runs is kind of wasteful -- you either lose a lot of energy in the wires or you need extra thick cables, so I wonder if the best way to do this is to have a high voltage line (AC or DC, it doesn't really matter) that goes to an outlet that has its own self-contained switching power supply and a bunch of low-voltage DC outlets.
Transitioning to this sort of system would actually be simple, you'd just have to make DC power supply boxes that plug into a regular 110 or 220 AC outlet -- sort of like multi-port USB power adapters, but designed for more power and probably higher voltages: perhaps +/- 12 volts and ground.
A more sophisticated system might be that the DC power supply can supply a different voltage/current to each port, and it negotiates with the device to supply to current power. (I think this is basically how DC fast chargers for EVs work -- the car tells the charger what it can accept, and the charger supplies that the car.)
Maybe "dumb" devices that don't know how to do the handshake just default to 5v DC or something.
Connect a hefty DC power supply to a power strip and just use that? Get a power strip of some obscure country for your DC so that you don't accidentally mix up 120VAC appliances with it.
USB-C sucks, I break a USB-C cable a week. They're physically too weak. I've very rarely broken 120VAC plugs or cables.
Also you can't exactly have a USB-C PD power strip of 10+ plugs without it costing a fortune because of all the negotiation needed per-port. Now they're onto some GaN bullshit just to make the PD adapters smaller.
The standards are a shitshow, there are incredible number of non-compliant USB-C cables.
802.3at PoE is slightly better, you can get 24+ ports for a couple hundred bucks, most cables advertised to meet PoE specs do in fact meet them.
But really the best would be straight up 48V on 2 rails and a bunch of plugs. No negotiation, no bullshit, no GaN, just 2 wires. Equipment, cabling, power strips would be dirt cheap. Individual devices can have very compact, efficient buck converters to get the voltage they actually need.
You can even get Anderson Powerpole wall sockets: https://powerwerx.com/powerpole-connector-outlet-box-coverpl...
I lived on a boat for a while and I used almost exclusively DC - it worked out pretty well. I used hard wiring and cigarette lighter plugs and that worked fine. The problem with wiring a house is that DC losses start to be huge over decent distances (100+ feet starts to be really tough.) I feel like that's one reason why DC is only really standard on cars/boats/motorhomes.