Some black holes grow much faster than their galaxies

Nearly every galaxy has a supermassive black hole. The few that don't have had theirs ejected during a galactic collision. That's because galaxies and their black holes have formed hand in hand. There is still some debate as to whether galaxies formed around the seeds of supermassive black holes or the other way around, but there is plenty of evidence to support the idea that the two evolve together.

Raccontata daphys.org