Mechanical switches aren't even reliable for this because of how 3-way switches work (their state doesn't indicate the state of the light). Unless you remember which are 3-way and which are single, you can't trust any of them. With smart switches in the same locations this is a non-issue.
An interesting thing is switches where you can't see if they're on as easily, such as the outside front lights, are for the most part fully automated (based on timer/door/motion and/or camera object detection) and we basically never touch the switch at all.
It's important to be consistent, though, since you technically can program the switches to do anything. In my house pressing up once turns the light on as you'd expect, but in some rooms the light will be less than 100% or have a warmer color temperature at night. Pressing twice turns on max brightness (or something similar, such as: 5000K color temp; also turning on the lights an adjacent room; turning on _all_ the backyard lights). I rarely use 3, 4 or 5-taps except for a couple special things (eg: 4x off on my office switch puts my PC to sleep; 3x on one of the basement switches activates a "party mode" my kid loves).
It is an aesthetic concern. If you have two light switches next to each other, they can get out if sync by being in different positions but representing the same state (light on or off).
That would be very ugly.
They look like a push-button, are therefore always "aligned", though the electrical switch alternates between open and closed.
Plus the momentary switches are always centered, they look fine next to traditional switches in either position.
I've lived there for over 5 years, and I still regularly press the wrong switch where there are two or three next to each other.
I have some of these:
https://www.thesmartesthouse.com/collections/800-series-z-wa...
(Third photo shows a side view.)
They can't be in different physical positions. They're momentary switches. When you press it up then release, it goes back to centered. The only indication of state on the switch is the (configurable/optional) little LED at the bottom of the switch. I have mine set so it's white if the switch is off (helps you find it in the dark), and off when the switch is on.
So if you have any 3-way switches in your house (I do!), it's actually an improvement as far as your concerns.
This sounds great. Can you provide a pointer or full search term to getting these ?
I've got a mix of the "Zooz ZEN71" for places where I need to switch larger loads (e.g., bathroom light and fan, all my outdoor lights) and the "Zooz ZEN72" elsewhere as it supports dimming.
Like it's an absolute requirement that they show a different physical position when on or off?
I've got some relatively cheap z-wave switches. They're only momentary, but up is on and down is off. When they're off, I have them configured to show a small white light on the bottom. So my indication of switch state is "small light = off, big light in the middle of the ceiling = on".
The switches _can't_ be out of sync with their state because they are directly controlling the attached lights. If anything were to somehow get out of sync, it would be home assistant.