There are black holes everywhere
Would it be surprising to know that there are millions, if not billions, of black holes in our Galaxy alone? And the chances that each Galaxy has a few of their own is a lot to grasp. The closest supermassive black hole to Earth is Sagittarius A which sits at the core of our Galaxy; however, there are many others within space, particularly the stellar black holes.
According to a scientist, there are no less than 100 million stellar black holes in the Milky Way. Scientists are still studying the other types, but there are chances that many of them are within our Galaxy alone. And if there are about 100 billion galaxies in space, you can imagine how many black holes there are in total. Do you want to try to calculate? Knock yourself out.