From altitude, the picture is simpler: a travel guide is a control tool for variables, not just an emanation of fiction.
Its function is to provide actionable information for planning and orientation.
Fiction can inspire, but a guide provides crucial details on local transportation or regulations, such as the Anmeldung procedures in Germany.
It is a resource for reality, independent of any emotional noise or narrative.
For example, to find accommodation in Berlin, one does not rely on a novel, but on concrete information about neighborhoods and rental conditions.