The simple fact is, the starting conditions for the Big Bang, according to the laws of physics we know from observation and experiment, could never result in a “Big Bang”. Those conditions would instead result in an extraordinarily massive black hole from which nothing could escape.
Scientists have to imagine that the laws of physics must have been different at that time to allow for a “big bang” instead of the usual result. However, that violates uniformitarianism, one of key postulates underlying all of science. Thus, their clinging to this “big bang” hypothesis undercuts just about everything else in science, since if the hypothesis were true, uniformitarianism could not be taken for granted, and all science based on the assumption of uniformitarianism would be put into question.
And God said, “Let there be light”.