It's actually not uncommon for a galaxy not to have a black hole. In fact, most smaller galaxies do not have a Supermassive Black Hole (SMBH) at their center.

The largest galaxies such as our own Milky Way, on the other hand, are expected to house SMBHs. These black holes are so large they can account for several hundred million or even billions of solar masses. As such, they dominate the centers of their respective galaxies.

However, there is evidence to suggest that galaxies with dormant black holes may exist. Observations of galaxies have revealed the existence of cores with no detectable X-Ray or radio emission which would indicate the presence of an active Supermassive Black Hole. It's possible that dormant SMBHs make up a significant fraction of the black hole population in the universe.