It's probably also because a lot of people sit in rooms which are poorly lit. Part of it is probably because it's really hard to establish proper lighting with modern LEDs. This is anecdotal, but our lamps haven't really changed in the way they are designed, We now have six lamps where we had three before, and there is still "less" light in our living room because LED's create and emit light differently.

I usually work with darkmode at home, and light mode in the office because our office is basically the surface of the sun.