You seem to be assuming that the Big Bang is a fact, whereas it might well be an article of faith, as you put it. It started off with a misunderstanding, that the redshifting of light meant an expanding universe. Hubble, the discoverer of redshift, argued against expansion and favoured the tired-light theory.

Dark matter and dark energy are speculative hypotheses, which were suggested because the observable universe does not conform to the predictions of Big Bang theory. Rather than re-examine the theory to see if it had flaws, scientists decided to stick with the theory and hypothesise these unobservable phenomena.

The best writer on Medium arguing agaist Big Bang theory is Glenn Borchardt. You should follow him. Here's a link to his latest article:

https://medium.com/@glennborchardt/tired-light-theory-supports-infinite-universe-theory-9417221f865f

I've written a lot about this in the past. I can send you links if you like.