Olber's Paradox covers this case also. Obscuring matter would not make the sky dark. Any matter in your line of sight would also itself "observe" a hot sky, jus

Olber's Paradox covers this case also. Obscuring matter would not make the sky dark. Any matter in your line of sight would also itself "observe" a hot sky, just as you do. Any such "observing matter" would reach equilibrium with incoming energy by re-radiating that energy at the same temperature. An infinite Universe looks like the surface of a star unrolled in your sky. All matter in the volume is baked, and re-radiates, at this intensity. I grant you only a moment to witness this spectacle, before you yourself reach equilibrium temperature with your sky.