Supply chain and logistics. We’d start to see where the biggest risk points were and use that to diversify risk and also rank failover. We could make predictions about how the supply chain would be disrupted based on individual suppliers/movers/warehouses/etc having events that affected their ability to perform. You start to see how much some suppliers rely on each other, etc. Holy hell did Covid make that crazy!
I think anything that has physical {nodes} and {edges}, where all things in each category are alike but very distinct from the other category, and connectivity is only achievable via a limited set of (not free) paths.
E.g. telecom networks, electrical grids, travel networks (including logistics), etc.
All of these feature a very different node (usually a system or capital asset) vs an edge (usually a wire or constructed path), and insight into the structure is economically valuable.
(That's talking to more traditional uses of graph theory, less-so to modern knowledge graphs)
