Some folks believe that dark matter is primordial dark matter stuff that can be tiny atomic size to ultra massive size. A primordial black hole has to be made of different material than visible matter fed black holes since there wasn't enough time to grow to such enormous sizes so soon after the big bang...
they think.
Only one part in a billion of matter remaining from the matter anti matter annihilation survived which is the visible matter we see. What about the 999,999,999 remainder of disintegrated annihilated matter? Much of it is energy but a small amount is the strange debris that might be primordial black hole stuff or dark matter. That dark matter out numbers visible matter by 70 to 90% compared to the small amount of visible matter.
If this sounds familiar congratulations, you understood me the first time around 10 years ago. Of course I could be wrong but thats the way I see it. Of course I can't see dark matter. Some say primoridial black hole stuff is less dense than than normal black hole stuff.