The advantage to believing in infinity is that it explains an infinite number of different observations and nothing can contradict a well-contructed infinity...and so infinity does not make unique predictions of future possibilities.
Notice that you mentioned a random fluctuation in an empty void as starting the universe, but space did not yet exist and so there was no such thing as a void. Nothing, you see, is an abstraction that science uses to explain the presence of space and the absence of matter.
The universe did not really begin as a matter fluctuation in space but as a fluctuation in spacetime and that fluctuation was a very compact space and matter source. Expanding is a bit of a misnomer since that term implies that the universe expands into a space outside of the universe, which of course is impossible.
And so it is certain that you will continue to use infinity to explain infinity, the ultimate do-loop, but it is not clear to me how infinity helps to predict the possible futures of sources...
