I think "night vision" is different from dark mode. It's meant to prevent your eyes from adjusting to the light - so you can still see the stars - rather than just being easy to look at.

Just to add, photoreceptors in the eyes consist of rods and three types of cones. Rods are what do the majority of the work for night vision and are nearly blind to long wavelengths of light (red).

It's so that you don't lose your dark adaptation. See: https://www.nps.gov/articles/dark-adaptation-of-the-human-ey...