I know enough about power systems to know that we're going to hit a hard limit on how much max power we're going to be able to plumb into a computer soon.

A single North American power circuit is approximately 120v and limited to 15A. The numbers wiggle a little from place to place, I've seen many that are running 115v or even closer to 110v. The 15A limit is not quite accurate either, since it's not recommended to load a circuit more than 80% for any continuous load, so your realistic maximum continual draw would be around 12A.

Some newer homes are being built with 20A, but most homes are still generally using 15A breakers.

At 120v, on a 15A circuit, you shouldn't consistently pull more than 12A, or 1440W. The line will max out at 1800W when the breaker/fuse will start to trigger.

So as power supplies hit 1200 to 1400 watts, you'll need to ensure that nothing else on the circuit will draw any significant power. A few displays and whatnot are fine, but with a 1200w PSU, you can't exceed 240w of additional draw while operating within the recommendations.

There are a few solutions to this, the obvious one is move to 20A, which can draw 1920W within the recommended power draw for the circuit, so you could have an 1800w system and about 120w of additional items before hitting the recommended limits, and 480w of total overhead before the breaker goes. The downside is that such circuits require thicker cables in-wall (12awg when 14awg is far more common in homes).

One option I'm aware of that nobody seems to consider is that in NA, the power delivered to the home is approximately 240v split-phase. 240v is generally only used for things like stovetops and ranges, electric dryers, water heaters, resistive heating in forced air furnaces, and air conditioning/heat pump systems. Though, it is entirely possible to convert a simple outlet to 240v. To be safe, you will need to get new receptacles, but you can reuse the wires already in the wall for 240v. I believe the NEMA 6-15R is the one that's rated for 240v operation in NA, and it's not dissimilar to the standard NEMA 5-15R that is the typical "North American" receptacle. However, a standard plug (aka a NEMA 5-15P) will not fit into the 240v receptacle. Any outlets on the same circuit would need to be changed so a 120v only device does not get plugged into the 240v receptacle. You can wire it for 240v at 15A which can provide up to 2880W of power without rewiring the house.

The trick will be to find a NEMA 6-15P to C13 connection for the PC and peripherals, and double checking that they will accept 240v power (all monitors and whatnot need to be set up to accept 240v power). On older power supplies, this is a simple switch on the outside of the PSU, though newer units will be switched, so they will detect the input power automatically.

I'm not recommending anyone does that, but if you do, talk to an electrician to ensure you're complying will all local ordinances.

Despite that, it is an option that most don't seem to consider.

Personally, I need to have some rewiring done in my residence and I'm going to see if I can get a dedicated 240v 20A single receptacle circuit installed for my computer, with the appropriate receptacles and everything.

To note: most 240v connections also have a neutral line (like what you would find with an oven or dryer), which the NEMA 6 receptacles do not have, they are 240v only. This, along with the fact that most 240v receptacles are rated for 30A+, makes them generally very large. The NEMA 6-15R and NEMA 6-20R are the 15/20A versions of 240v AFAIK, and they're not really any larger than a standard receptacle.

Oh yeah, modern PCs use a lot of power under load, I was renovating the main room in my condo in the middle of Canadian winter and was keeping the place warm by having two PCs mining crypto since I didn't have a baseboard!