I was wondering about black holes created from dark matter only. I mean: if there's 5x as much stuff that has mass (and, thus, can form black holes), there sho

I was wondering about black holes created from dark matter only. I mean: if there's 5x as much stuff that has mass (and, thus, can form black holes), there should be 5x as many black holes - at least, that's what I'd expect in the absence of some specific reasons. But as far as I know, we haven't seen them.