Big Bang Theory

[Truth Matters]

Why is embracing a Materialist belief (a belief that cannot possibly explain the absolute physical beginning) better than a fully sufficient and rationally plausible explanation?

Because the "fully sufficient and rationally plausible explanation" you would be proposing explains nothing. The Big Bang model explains, with observational evidentiary support, how the Universe expanded from the Planck Era to what we see today. That it doesn't touch upon the initial "absolute physical beginning" is unsurprising; it's akin to Evolutionary Theory having nothing to do with the origin of life.

The goddidit model, on the other hand, tells us nothing useful, such as how the god did it, nor does it have any evidence whatsoever to support it. On the contrary, all the physical evidence actually reveals the exact opposite.

Bottom line is we can trace the expansion of the Universe right back as far as we are able with current techniques, which are improving by the way. So far, we have seen that the Universe operates according to physical laws behaving in predictable, understandable ways. Even if we haven't (yet) captured the precise moment of its birth, for what reason is there, other than to prop up an increasingly-obsolete fairy tale, to suppose that there's anything fundamentally different about that moment?

I've met my burden. Now justify your belief?

The person proposing the entity extra to the known system, which operates perfectly well without the addition, is the one who carries the burden of proving its existence.

Big Bang explains nothing about the causally antecedent conditions prior to Big Bang. Science stops cold at the singularity boundary, but reason does not.

Material, time and space began to exist
Material, time and space cannot be it's own cause.
The fact that it BEGAN means it cannot self-exist (self-existence is rationally necessary)
Where is that causal agency?
Any sufficient causal agency must have the necessary attributes of being Timeless, spaceless and immaterial - and capacity to create a contingent Universe. God fits the criteria perfectly. Materialism precludes that which is necessary for any sufficient causal agency.