Light photons travel at different intensities, and they tend to scatter. When these photons scatter, this becomes the light that illuminates our rooms.
Furthermore, the sun is really bright. If the sun exerts the smallest amount of light, it is so powerful that it can light up a great surface area.
Check out "Our rooms become brighter in the day time although there is no direct sunlight in our room why" by "manishgzp9850" on Brainly for further information!