Also, what if so-called "dark matter" or "anti-matter" interrupts or degrades certain parts of the light spectrum? How far do UV photons travel in our current knowledge? The questions go on and on and I don't think physics equations are the end all for the answers.
To answer a question about are we alone in the Universe in the movie Contact, the father said, "If so, what a huge waste of space". Personally, I believe something created the Singularity for the Big Bang just because. It could have its own reasons. It could even be a child playing marbles as in Men In Black.
Do a Google on Barry Setterfield. The speed of light is much slower now than in eons past, due to the increasing zero point field energy and exponentially growing numbers of virtual paired particles popping.