As long as (AM)OLED displays have been included in phones, it seems like the most popular feature request for apps has been dark/black themes. Between the power savings, the attractive bezel-blending, and the simple convenience of just not being blinded at night, everyone from enthusiasts to night owls has enjoyed these gloomy additions. But right now, it's all still a per-app affair that most first-party Google products don't participate in. But, if it were possible, would you want a system-wide dark/night mode setting in stock Android?
Even the Pixel Launcher has an automatic dark theme, together with a recently-added manual toggle in Android P, and in the last week or so, the YouTube app also got its own. But those of us that prefer things a bit darker have long dreamed of a unified, system-wide setting that was somehow able to tell even third-party apps to switch over to a dark background, if possible.
Back in the day, half the reason I would put forward the effort and maintenance required to root/ROM/Xposed was to force as many apps as possible into using a consistent white-on-black theme. OnePlus has long given OxygenOS a dark theme toggle, which I'm a fan of, but it only really affects the company's own applications. Personally, I'd love if more of Google's first-party apps supported dark themes, and a system-wide flag or setting configurable for the time of day or sunset/sunrise would be incredible.
If next year's Android "Q" could stand for Quite Black, is that something you'd want?