The math is beyond me, I am sure that it is also beyond you, but legitimately the "material stuff" could have come from nothing. The CMB has *** lot of evidence packed within it. One important part of the evidence is whether the universe is "flat", The other two options are "open" or "closed". To the best that can be measured the universe is flat. And that has consequences. It means that the total energy of the universe is zero. Which means that the energy of the Big Bang does not violate conservation of energy laws.
The problem with a steady state is that matter on its own will be attracted to other matter and eventually all mater would be in one place.
And you still did not answer my question. Your explanation is just an ad hoc one.
As far as cosmologists can tell, space is almost perfectly flat. But what does this mean?
astronomy.com