I don’t want to get into the habit of not finishing projects, but this is hopeless. Cell fracture deleted random chunks of the wall and created floating vertices and edges everywhere. There is also lots of this:
I really want to do something else, but I also want to actually finish something for once.
I was thinking you could do it like this, where it’s smoother at the base, then around where it collapsed and higher up it has less mortar keeping it together.
Maybe this can help you get started with the cracks. It’s just a basic set up, you can easily create a mask, so the cracks aren’t all over the place. Add some color variation. Some small dents and a larger scale, slight ‘waviness’ to the surface, etc…