Really sucks to be 2nd class citizens, no? The way Evernote closed the 5-year old thread even though Windows users are still waiting (you wouldn't close the thread if dark mode was only released on iOS, no?) and how ambiguous the help article regarding Dark Mode on Windows is (not even a promise that it's coming or that they're working on it, it just says "got better things to do") implies Evernote thinks their work is done here. We're probably gonna get it too but we can probably expect in the same 5 year time frame I guess. We're just not that much of a priority.
Mac people though, ah,