Dying "red and dead" galaxies as the start of Universal contraction and collapse (Big Crunch) in a cyclic multiverse..
According to Quantum FFF Theory (Function Follows Form), not the giants- but the smallest black holes reside in the center of galaxies.
According to Q-FFF theory Black holes don't merge because there is always a Birkeland Alfven current circuit in between two BHs and plasma pushing the BHs away from each other simply by two plasma jets!
So it is assumed that only in case of dead galaxies with lots of smaller black holes in the center, merging becomes possible, due to the absence of linear magnetic and electric polarization based jets between two Black holes .
Also: Birkeland -Aflven current systems are gone.