From a higher perspective, the picture is simpler: tourist guides are not just a sub-part of fictional inspiration. Fictional inspiration is often just noise if it is not followed by concrete action, which is not the case with guides.
They provide practical information and controllable constraints, such as itineraries, budgets, and transportation details, turning a diffuse idea into a feasible project.
For example, a novel may evoke the beauty of the Black Forest, but it is the guide that will detail hiking trails and accommodations, moving the trip from fantasy to the discipline of planning.