Agree on all of that. I generally use X11 "Wheat" (F5DEB3) for emacs and maybe "White Smoke" (F5F5F5) for terminals.
My monitors are set to maximum contrast, and 0% brightness in a fairly dim room, or maybe 15% in a bright office.
People who think they prefer "dark mode" probably have their monitors set to be like a blazing sun. Ideally, the intensity of "white" should be like a sheet of paper, not like an arc lamp.
I used any number of green-on-black and amber-on-black terminals in the distant past, and even on white VT100s I preferred white-on-black because the intensity of the screen was so high and the quality so low when I tried to use black-on-white.
On CRT you needed a high refresh rate to make black-on-white work. (Irrelevant on LCD)
I switched as soon as the PERQ and Lisa/Mac came out, with good quality high refresh rate black-on-white displays and I've never looked back.
For me, the huge advantage the Mac had in the 1980s and early 90s over not only the Amiga and Atari ST but also over DOS/Windows was nothing at all to do with the CPU speed or price or even the software, but in the massively better quality of the video displays, which made them much much less fatiguing to use.