[lutusp]

> There is no theory stating that the singularity of which the big bang is theorized to expand from was brought into existence from a collapsing star.

Not an issue, only that a singularity can exist, and therefore might come into being in the present.

If in a consistent physical theory we grant the reality of a singularity arising from very high matter density, then this narrows the range of possibilities for their nonexistence in the present.

So we have conventional densities easily explained by current theory, and we have the possibility of a singularity as an endpoint of increasing matter density, which narrows the discussion to the means whereby a mass might collapse past the critical density. I'm just saying this increases the burden on those who try to argue that the transition isn't possible. Especially given the absence of evidence in favor of, and plenty of evidence against, the stated thesis.