Light pollution is so bad in many cities that no more than fifty stars, or even fifteen, depending upon night viewing conditions, are visible to the unaided eye. In many cities, you can't see any stars at all at night (or the evening and morning "stars") without going to a park that gives you some distance from bright city lights.
Suppose that light pollution becomes so obstructive, from both direct and indirect sources, for instance, by light scattering from aerosols and particulates in the atmosphere, that no one on the surface of the earth could see with unaided eyes any stars at all. How would our conception of ourselves change?
Well, for one matter, no one would be able to have experience that connected them to the ancient Greek tradition of astronomy, or to the ancient Greek theology, as both these intellectual traditions derived from experience and knowledge of the night sky.
And no one would be able to have experience that connected them to the Romantic traditions in Western religion.
But loss of these historical traditions would be, I think, of less significance than impact on the human psyche (after all, those traditions could be--and probably would be--reinvented if humankind still had the ancients' night vision of the stars).
Would not the loss of the night sky reduce humankind to the world of animals, who look (or hear or smell or feel) no farther than the forest floor or the prairie horizon?