The universe didn't form uniformly, so if a bunch of dark matter formed as a clump, it would remain like that.
Also dark matter is gravitationally affected by light matter, which does interact. My intuition tells me that the interaction of light matter that creates clumps of light matter will also create clumps of dark matter indirectly.
* note: 90% my dark matter knowledge comes from HN. I'm just spitballing here
What happens to a comet that enters the solar system if it doesn’t hit anything? It leaves the solar system with the same speed it entered it with. Dark matter cannot hit anything.
Also dark matter is gravitationally affected by light matter, which does interact. My intuition tells me that the interaction of light matter that creates clumps of light matter will also create clumps of dark matter indirectly.
* note: 90% my dark matter knowledge comes from HN. I'm just spitballing here