> the first LCDs that came out were very dim compared to the CRTs they were replacing

Maybe this was true on laptops, but I remember my first experience with an LCD on a desktop was with the G4 iMac in 2003. I remember it came out of the box set to 100% brightness and it hurt my eyes to use it. It took me a little while to figure out how to turn it down so I could use it pain free.

Before that iMac I had a Thinkpad with Windows 2000, which was very gray. I don’t remember having problems. The shift to white seemed to come after LCDs were already pretty capable.

In my memory dark mode seemed to come much later, as people would use their smartphones in bed and be blinded by the light coming off a white webpage background. There was a vocal minority that then pushed for dark mode on everything. It is possible that before that was the idea that dark mode would use less energy and we should do it to save the planet. I seem to remember that fad for a while, but don’t recall where it fit in the timeline.