I completely agree, not to mention the questionable merits of dark mode in general. There are numerous third party solutions too, if someone really wanted them.
Dark mode, besides looking cool, is sometimes promoted as healthier to the eyes, or using less energy to display the same content. These are the claims I think are questionable. The accessible color features will be cool.
I'm confused about what you find questionable about this, are you saying we shouldn't accommodate people with disabilities?