I'm having some trouble coming up with plausible inferences from that fact. Do you mean to imply that "when you have a hammer everything looks like a nail"?
The category theory for programmers crowd argue that categorical diagrams (annotated graphs) are the right way to reason about software to gain insights — and the rest is describing the equivalence between functions in a type theory and maps in a category.
Your mental model of directed graphs is a functional model.
In the more general sense that may be true, but I was talking about Factorio specifically, where I'm using the graph representation to do the analysis.
Or rather, just because a functional interpretation exists doesn't mean I actually reach for the toolkit filed in my memory in the box labeled "functional stuff". In practice I mostly reach for the boxes I've filed away under "linear algebra", "graph theory", and "circuit design", which aren't things I typically reach for when I'm actually doing functional programming.