Big Bang based upon metaphysics and ideology to select from an infinite number of possible models. The particular metaphysics and ideology are deliberately anti-purpose and thus anti-God. The metaphysics takes the form of the ‘Copernican Principle’ which conflicts with observations.
Big Bang can’t explain the existence of any stars or galaxies. However, we’re told it explains all observations — NOT!
There are many other unresolved issues as well.
Recommended book: Dismantling the Big Bang