Current cosmology (big bang theory) is coming to an end.

No. It only means Galaxy formation models are wrong or missing
some key aspect. Present models begin with the assumption
that stars form and coalesce into galactic structure thru gravitational
collapse. Then further collapse results in black hole formation. In
my opinion this is where these models err. I've never understood why
the range of collapse structures ( in the early Universe) ends with
massive stars. It seems
reasonable to allow for the formation of a range of black hole masses
also; including galactic nuclei where matter densities differ.