From an outsider... why does it seem that easy to you? They had a team of OR people working on this and presumably the money to buy a gurobi license.
And according to the PR they did not use gurobi (or any sota mip solver), just their in-house lp solver in combination with shortest path algorithms and the fix-and-optimize heuristic.
Likely your particular use case will not fit their model anyway (for example you may want to consider contracts of affreighent along with leasing entire vessels).
So yes, or scientist and gurobi will definitely win.
This is just a PR article, it's hard to say what they did or didn't try before arriving at this solution.
Academics care about proving optimality. Businesses care about their own specific use case and not synthetic benchmarks.
This does not align with my experience of people working in OR.