Please note that in the explanations about WHY distant objects in space work the way they do, we only have ideas, possibly theories, hypotheses, and all sorts of other goodies. What we don't have is FACT.

We may have fact in WHAT we observe, but we don't really have any fact in the reasons that it is the way it is. Such reasoning MIGHT be accurate, but there are too many variables that are unaccounted for, for us to be anywhere near certain about the WHY behind almost anything distant out there.

In other words, it is all really just guess-work.