Yeah Android has some features and apps in this space. This iOS mode is an accessibility feature. I guess for some people a pure red screen helps them see it better?

This feature is not intended as a "night mode", it's very extreme. It also makes anything that has no red channel in its color disappear (although this is rare). I found it's a better night mode than actual night modes. But it's best if you're just reading text, for video or games it's probably too extreme.