Then why does macOS have dark mode when all Apple computers that have a screen are LCD? Why does Windows have dark mode when nearly all screens are LCD? All iPads have LCD screens and dark mode. Why did Kobo add dark mode to the Elipsa? Why do Kindles have dark mode? It saves no energy on any of them.
Amazon only puts dark mode on newer or higher end Kindles and promotes it as a feature to sell them. People are willing to patch or add additional software to their Kobo reader to get dark mode.
If this was a feature primarily for energy savings would they have spent the time adding it to devices where it doesn't save any energy? Why don't either Apple or Google turn on dark mode in low power or energy saving mode? This is why:
https://www.purdue.edu/newsroom/rele...r-linings.html
I can only assume that companies add dark mode because people want it and it sells devices (my opinion).
I have had to ask myself why I am spending so much time and energy replying to you. You rubbed me the wrong way when you said "Then the screen contrast or brightness is wrong" on my iPad. You can't possibly know how my eyes are or how I see, yet you say that as a statement of fact. How can you prove that? You say that there is no human advantage to dark mode but offer nothing to back it up. It's a pretty sweeping statement that dark mode is useless to all people and they just have to adjust the brightness correctly. Show me a study to back it up. Don't use some random internet article that just says "studies show...", make sure there is a link or reference to an actual study.
"I'm not objecting to anyone having the personal preference to use dark mode. I'm just pointing out that the current reason for the promotion of it is power saving on OLED phones and tablets. It's nothing to do with eye conditions."
It might not be anything to do with eye conditions, but I think it is to do with giving people what they want (my opinion). See link to study above.
Do use what suits you. Be aware of nocebo and placebo effects!
Do you have any evidence that this is a placebo effect? Again you don't offer anything to back it up. Even if it is a placebo effect it's still real to me.
You offer a lot of "facts" with nothing to back them up and I really object to someone telling me that what I experience and feel is somehow wrong or non-existent. You can't possibly know what I experience or that I can fix it by adjusting something like the backlight (or frontlight).