Why does the Sun's brilliance cause the blue sky, overwhelming distant starlight during the day?

Its light scatters through the atmosphere, creating a pervasive, brilliant background veil.

The visibility of stars during the day is defeated by the Sun because its intense light reaches Earth and is scattered by the gases and particles present in our atmosphere. This scattering effect is what produces the diffuse blue glow we perceive as the daytime sky. This bright, pervasive background effectively washes out or drowns the comparatively faint light arriving from distant stars, making it impossible for the unaided human eye to detect the necessary contrast required for visibility. Essentially, the sky itself becomes the primary source of overwhelming light pollution originating from our nearest star.