Is there really any problem with an infinate regresion of universes?

[Mudhammam]

Because, if universes begin with a big bang from a singularity, as is commonly (but not universally) accepted, then the current universe must necessarily collapse in order for the next one to begin.

Philosophically, there's nothing prohibiting eternal universes. But, our observations so far indicate otherwise.

There is no observatable data that show the universe began to exist. The only observation is that the universe was once hot, dense, and very small. Some people and scientist extrapolate this information to a beginning without a proper justification because the known physicals laws are no longer valid at such dense hot states . The scientist will freely admit this.

Still, it's reasonable to ask why it didn't remain hot, dense, and very small, and to term the conditions that resulted in the expansion of the Universe we perceive as the beginning of spacetime existence, no?