I think, rather than “category theory is about paths in graphs”, it would be more reasonable to say that category theory is about paths in graphs up to equivalence, and in particular about properties of paths which depend on their relations to other paths (more than on their relationship to the vertices)*. If your problem is most usefully conceptualized as a question about paths (finding the shortest path between two vertices, or counting paths, or something in that genre, you should definitely look to the graph theory literature instead)
* I realize this is totally incomprehensible, and doesn’t make the case that there are any interesting problems like this. I’m not trying to argue that category theory is useful, just clarifying that your intuition that it’s not useful for problems that look like these examples is right.
I think, rather than “category theory is about paths in graphs”, it would be more reasonable to say that category theory is about paths in graphs up to equivalence, and in particular about properties of paths which depend on their relations to other paths (more than on their relationship to the vertices)*. If your problem is most usefully conceptualized as a question about paths (finding the shortest path between two vertices, or counting paths, or something in that genre, you should definitely look to the graph theory literature instead)
* I realize this is totally incomprehensible, and doesn’t make the case that there are any interesting problems like this. I’m not trying to argue that category theory is useful, just clarifying that your intuition that it’s not useful for problems that look like these examples is right.