The best I can explain the actual physics would be that some interactions at the impurities cause electrons to form "wires" of superconductivity in one axis across them. This isn't unheard of in existing materials, but the problem is that in those materials they tend to be isolated "wires" and even tiny disturbances throw the whole thing off.
But that in this material, the way these impurities forms creates a mesh of these "wires" where charge/magnetism can jump. Subsequently, it's resistance to disturbances climbs dramatically, as alternative superconductive paths can be taken as any disturbance propogates through a given part of the material.
They now believe we can use this knowledge to intentionally construct even more materials with this behavior.
And because I never stop finding it hilarious... Part of the preparation of the material is repeatedly taking a piece of scotch tape to a thin strip of the graphite, removing the top layer to make it extra thin.
The parts of my comment that are not quotes are just reasons to not immediately dismiss it, like many other "keystone" technology discoveries.
https://www.technologyreview.com/2008/10/23/217918/x-rays-ma...
Graphene was initially created using scotch tape, however, and it remains a reliable and simple method of getting high quality graphene for lab experiments.
Because superconductivity is not a property of the normal structure of graphite, but it appears when a certain configuration of defects is formed by breaking the graphite, I assume that it is difficult to obtain twice the same properties.
Moreover, because superconductivity appears in a fragile crystal, it could not be used for flexible cables, but only for rigid PCBs or inside integrated circuits. Because the superconductivity is on the surface of the crystal, not in its volume, it will not be able to carry high currents.
Nevertheless, it is likely that after some years the reproducibility problems could be overcome.
Neither superconducting graphite nor lead apatite appear promising for high-power applications, but one of them or a similar material could lead to significant improvements in integrated circuits and PCBs.
Compared to modern chip manufacturing processes, cleaving and stacking pyrolitic graphite in a controlled way seems quite doable. I'd like to be optimistic, at least!
Other materials, like glass, oils, metals, liquids, can serve as an embedded substrate, which can then be encapsulated by a flexible surface material. LK-99, with as much lead content as it had, would be difficult in terms of consumer safety, but graphite is trivial. If you could produce a sufficient quantity of superconducting particles to embed in polymer, then insulate cord, tape, or other flexible form factors, you wouldn't have to worry to much about disposal and recycling. LK-99 would be a possible toxic addition and probably not great for the world, even with superconducting features, in a public commercial context.