Progress means change and no other science needs to change more than cosmology.
The same imaginary ideas as dark matter  dark energy  dark forces and black holes
taught as real active things or forces more or less ‘proven’ rather than the assumptions
that they really are.
Let us assume that all the universe has always been the same size as is seen today but without any material, how could material eventually occur? It is undeniable that space moves, since all material, which we know is almost 100% empty moves all the time,
whether  it is a planet or a cricket ball. Before any mass existed moving space collided
and in doing so created spin. Spinning space now contains energy in permanent units spinning forever and in doing so exerting the pull on space which is gravity.  Not an attraction between masses. In this way materialisation occurred throughout the empty universe at its present size. Trillions of fundamental particles are constantly created in this way. Empty space is not nothing, once energised it is everything.
Big Bang relies on its version of how the redshift of light is caused by receding motion or expansion. Since mass gravity is known to weaken with distance as the same force is
applied to a greater volume. However as we have described above, each particle exerts gravity and there is no loss of power in the tiny shaft of space travelled by the light and so creates redshift. Light travels the same distance for the same time but encounters more space than normal altering the frequency and producing redshift.