Space appears dark because it is mostly empty and devoid of large sources of light. The Sun does emit light and illuminates the Earth and its surroundings, but as you move away from the immediate vicinity of the Earth, the sunlight becomes more dispersed and less intense. Additionally, space is vast and filled with a tremendous amount of empty space, which means that the amount of light reaching any given point in space is relatively low.
When we look up at the night sky, we see darkness with scattered stars because the light from distant stars takes a long time to reach us, and the intensity of their light diminishes as it travels through space. The observable universe is also expanding, causing the light from very distant objects to be stretched and shifted toward the red end of the spectrum, which makes them more difficult to see with the naked eye.
While there are objects in space that emit light, such as stars, galaxies, and nebulae, they are far apart from one another, resulting in vast stretches of space that appear dark to our eyes. However, with the aid of telescopes and other astronomical instruments, we can detect and observe these celestial objects, revealing the grandeur and complexity of the universe beyond our immediate surroundings.