The sun is the only known disc-like object to burn so brightly and seemingly unendingly. It's hardly comparable to any other light source in any meaningful way.
What in the world does the length something is emitting light have to do with the instantaneous properties of that light? Again, this is the whole "there is nothing else like X so if you object to my ascribing of special properties to X it is only because you do not understand that X is special" nonsense. It's illogical. This is about the wavelength of the sunlight shifting from the yellower region into the longer red regions, not about pointing out how special the sun is compared to other objects that also emit light.
You do understand what light is, right? It is a stream of photons causing sinusoidal fluctuations to the electric and magnetic fields of nearby space. The sun's great intensity just means that more photons are being absorbed by the earth per unit time than from most other light sources. But the properties of individual photons of a certain wavelength are independent of how many other photons are around it. So your mention of brightness is irrelevant, as well.
The sun is VERY comparable to any other natural light source, and so Sliver's question is quite valid. It is NONSENSE to explain away questionable claims by saying "because it's special."