You seem to be conflating two problems. The fact that many people stay up too late entertaining themselves doesn’t change how people as a whole respond physiologically to the presence and absence of sunlight, or how that ought to factor in to policy decisions.
The majority of year there is dark long before adults go to sleep. Adults go to sleep at same times as during summer, the dark is not making them going to sleep more.
For all practical purposes, sun is completely irrelevant to adults sleeping.
