As an American, I'd just be happy if we switched to 240v rather than 120.
Someone who knows what they're doing can also add a 240V outlet to any room.
We don't serve 120V to homes, we take 240V and split it. In fact, that's not the only time you use a mix of different voltages. You take that 120V, and then further transform it to 18-24V for things like doorbells and thermostats, or you use a power-brick at the wall to convert it to direct current to charge your laptop, phone, and other items. In none of those use cases would 240V really change your life. It's really only better at boiling water in counter-top kettles. I'm guessing we don't use more 240V kettles because we're not a tea drinking country and culturally people tend to use coffee machines that are "fast enough", but not slow enough to be worth switching over.
Ackchyually, we deliver 120V to the poles, not 240V. Then transformers at the poles near the homes split it to two 120V phases, 180° apart. So the difference between +120V and -120V becomes 240V. But the pole wires are still 120V.
"avoids eye contact as you patently explain that the only real benefit to three phase is for motors"
But really the US is a 240V system. we just split the phase and wire the house in two halfs. you should not even need to rewire your house. Just hook the neutral to the opposite phase in the panel, like magic you now have 240V in every outlet.
Don't actually do this it will end up killing someone.
As near to 100% as makes no difference every single house is already wired for 240v. In fact wired for it and using it: electric ranges, stoves, dryers, etc are all 240v.
NEMA even defines 240v receptacles/plugs for normal amperage: NEMA 6-15 (two horizontal blades: meh face) and 6-20 (one vertical, one horizontal: wink with other eye closed). Unlike the common 240v dryer/large appliance cords that are huge and bulky 6-15 and 6-20 are about the same size as our current 120v plugs. They have the same compatibility as 5-15/5-20: The 15 amp version fits in the 20 amp receptacle but the 20 amp only fits 20 amp. And it is impossible to plug 120 into 240 or vice-versa. Everything made for 120v (to a rough approximation) is also rated for 240v.
Unfortunately no one bothers to install the 6-15/6-20 plugs. There is nothing stopping any builder from doing it standard, especially in the kitchen. There is nothing stopping a homeowner/buyer from asking for it either. But no one does. Therefore there is no market for appliances that use these plugs. And thus no demand to wire for them.
It would likely take a push from government, manufacturers, the NEC, etc to push for supporting 240v for common appliances. Start installing them in new homes. Offering the 240v version of electric kettles and such.
Note: some European appliances can be wired up this way and will run fine because they tolerate 60Hz but not all of them.
The only NEMA 6 I have is on my table saw, and maybe the planer? Everything else is NEMA 14 (two hots, neutral, and ground). The upside of that is the bulb in your dryer, for example, can be a standard 120 volt bulb.
I'd also like to note that the locking connectors plug and unplug a hell of a lot nicer than the non-locking ones, at least at the 30 amp size (which is common for a dryer). They just operate much more smoothly, presumably because they aren't relying on friction to keep them plugged in.
You've got the cause/effect backwards I think. The high amp stuff needs 240v to avoid ridiculous amp requirements. The lower power stuff just defaults to 120 because that's the most compatible leading to the chicken-and-egg problem.
> probably in part because some stuff also wants a neutral?
I've tried to come up with reasons this might matter but so far I can't. The Neutral (or really L2 in this scenario) is the reference plane. It moves in step with L1 and so when L2 is high (+120) L1 is low (-120), but from the POV of the reference that's just -240. Same for the other cycle half.
In other words measuring voltage is relative in all cases. Unless you are measuring in relationship to the earth (an infinite sink for our purposes) you can't tell if you are seeing +120/-120 or +240/0.
Perhaps there is something that relies directly on the voltage potential between Line and Ground, I just don't know of any. Most things that are sensitive to an actual ground reference are electronics which run on DC and are separated from the mains by their power supply anyway.
Almost no one, but I had a 6-15R put in my kitchen. Then I imported a 3kW tea kettle from the UK, lopped off the plug, and put on a 6-15P. And now my wife doesn’t have to wait very long for her hot water.