Well, according to this: https://www.space.com/dancing-black-holes-merge

"Based on all the observations of gravitational waves, astronomers estimate that there are somewhere between 15 and 38 black hole mergers every year within every cubic gigaparsec of volume in the universe (about 1/12000th of the total volume of the observable universe)"

According to this: https://bigthink.com/starts-with-a-bang/40-quintillion-black...

"By combining information about stars, black holes, and stellar and cosmic evolution all together, astronomers have the first robust estimate for black holes in the Universe: 40 quintillion"

So, just for black hole mergers, it would be really, really rare. There are probably orders of magnitude more black holes that are just orbiting each other.

Neutron star and black hole statistics I leave as an exercise for the reader ;)