Accessibility request: dark/black theme/design

For accessibility reasons, to support users with eye disabilities it would be recommended to add a kinda high contrast mode, dark/black theme/design to apps. In general and to the stack exchange/overflow apps, too. There was a feature request on meta stack from 2016 with only the discussion if it is a duplicate, but nothing about it's reasoning and consequences. ? Please discuss and consider this request, which is still a valid!