A real life astronomer just gave you the simple, factual answer to the question that your kids will inevitably ask, and might have also been puzzling you since you were a child. https://t.co/E7E8nGXQ5Z
— Angela Mayfield for GA HD 67 (@pinkrocktopus) June 18, 2020
That the sky is mostly dark is also how we know that our universe is almost certainly not infinite, as if it were, the sky would be infinitely bright!