Final answer:
The Sun looks bigger and brighter from Earth than other stars because it is much closer to us, being the only star in our solar system.
Step-by-step explanation:
The reason the Sun looks bigger and brighter from Earth than other stars is due to its proximity to our planet. Unlike Proxima Centauri, which is the nearest star beyond the Sun and is 4.3 light-years away, the Sun is much closer, being at the center of our solar system. This close distance means the Sun's light does not have to travel as far to reach us, making it appear brighter and its physical size larger to our eyes than stars that are light-years away. The distinction of the Sun in our sky further emphasizes that the Sun is the only star in our solar system, whereas other stars appear as mere pinpoints in the night sky due to their vast distances.