That is a code thing and i actually think it has changed. My house built in 2016 has a nuetral in every switch box unless it is a box that only has the extenstion switchs in a 3-pole setup or higher.
That might even vary by state as well.
In the UK it varies greatly how lighting circuits are wired but isn't stipulated in the regs.
Older houses used a loop in ceiling circuit - line and neutral from consumer unit in and out of each fitting on the circuit with a twin from the fitting to it's respective switch (line and switched line).
Those houses that were later rewired used the same method or often everything was wire to junction boxes.
It's now common to see the opposite. Looping line and neutral to each switch and then a twin to the fitting with switches line and neutral (less connections at ceiling and fewer DIY cockups as it's difficult to make a mistake with only two wires, though I have seen it)
The house I grew up in pre dated earthing and everything was wired in singles...Line was looped in and out of every switch, neutral was looped in and out of every fitting and a switched single went between the switch and the fitting.
I am sure you would see similar things in the US as the contruction gets older. Ultimately as long as it is all done safely it is all just about making a complete circiut right.
@tentacle how did you get on here. I have a few use cases for your idea too. Also for info, I have a 4 gang Samotech 323 set up (all with load wires). I had to dremmel the holes in the face plate slightly to make them all fit. If you do use your snazzy faceplate shown above, bare this in mind. Ps, where can you buy that face plate. It's a cracker!
Hey @stueyhughes - this is obviously a massively late response, so apologies!
I have (I think) now sorted this out. The solution, somewhat predictably, was to get an electrician to add neutrals in my switch boxes. As I'm doing a pretty major renovation anyway this wasn't too big an issue as there's lots of plastering going on as well so it doesn't make a huge difference to me.
With the neutrals in place the world's largely my oyster and I've landed on a pair of SM323s for the two "real" lighting circuits and then I've also purchased a pair of these (on sale!) which will just daisychain into the live/neutrals and when I flick the switch they're connected to will generate an event in the Hubitat which I can create a rule off. So the front fascia will have two smart dimmers controlling the ceiling lights and two toggle switches which will control a floor lamp and some shelving lights (via turning on sockets)
The last of the work is drawing to a close so by mid-June I expect this to all be fitted and working. I'll update with pictures etc if I ever get there! 
The switches (and sockets) I'm planning on purchasing are available from Dowsing and Reynalds.
I'd be interested to see how you get on here. Just one point of note, when you say "flick the switch" will you use push button on off switches which looks like dimmers so essentially you'll have a 4 gang plate with what looks like 4 dimmers but in reality is 2* 323's and 2* push button on/off's?
Ps the new SM323 MK2 work with or without neutrals. Samotech claim that adding a neutral gives more control but I can't see any differences when a neutral is used. I actually prefer the mark 1
Ah- for the switches I’ll be using a custom order which will have two dimmers and two toggle switches:
Hopefully it’ll turn out the way I want but I’ll let you know!
I’m also not sure what the MK2 SM323 offers above the MK1 but I had to have the neutrals for the other modules so I guess I might as well connect them all up with L&N.
I used these on/off modules which looks like dimmers. If you mirrored this, your faceplate could have 4 knobs for an even look. Just a suggestion but I bought an equivalent from my local electric shop for a few quid each. https://amzn.eu/d/0ytYIBM
essentially, they're toggles
Oh, nice! I've not seen those before but they would definitely work for this, good suggestion!
Yeah I have a 2 gang version. One is a smart SM323 the other just an on/off pusher knob
