alt Hacker NewsIt was not a screen-saver. Less ghosting? Most likely. But the fact remains that reading text off of a light bulb blasting in your face all day sucks, and once upon a time people knew that... but "forgot" it when vendors shoved inverse color schemes on them by default.
"80's and 90's had a general concept of a desktop with windows as paper documents"
Yes, I noted that; but the analogy to a piece of paper fails because paper does not EMIT light.
Everyone with sufficient computing experience calls "light" schemes inverted. This was even documented in instruction manuals from the early PC era: https://imgur.com/a/aLV8tn0
Anyone experienced remembers that any 60Hz CRT is a flickering mess, especially computer monitors that used shorter-lived phosphors, and any old TV had terrible burn-in. That's why you want to reduce the amount of bright pixels on it. That's not a legibility thing.
A display is not a light bulb if you aren't specifically making it a light bulb against the poorly lit environment. There's no difference between reflected and emitted light, what you actually need is much better lighting in the room, so your display doesn't stand out when used on a brightness level that provides sufficient contrast (and just because working in a poorly lit room is unhealthy).
Moreover, a light scheme in a well-lit environment is less eye-straining, because your pupils contract and adapt to the light. If you're using a dark display against a dark background, your eyes adapt to the dark and then you're hit with the bright text. If you want to display more than just text, dark mode becomes a problem because most of the content (e.g. pictures, videos) is not largely dark.
tl;dr avoid excessive contrast and flickering. Everything else is individual eyesight differences, opinions, and snake oil.