One answer to this problem is that the night sky isn't dark at all. It's just less bright than during the day. Hear me out. As a species that evolved on this

One answer to this problem is that the night sky isn't dark at all. It's just less bright than during the day. Hear me out. As a species that evolved on this planet under it's particular conditions we perceive day to be bright and night to be dark because of the particular range of light sensitivity of our eyes. Too often science leaves the human observer out of the equation. It lets us feel like gods presiding over our universe but is a big mistake. All that said it's not unreasonable to question why the night sky is not brighter than it is.