The value of large format diagrams on walls is underestimated as a way of communicating essential concepts to a large community of people.
For a millenia (e.g. frescos, murals etc.) have been used to communicate common concepts to communities where the individuals didn't have the ability (let alone the time) to read the texts that provided the details.
It could argued that icongraphy proved an effective way of ensuring the main christian churches remained united (with people all seeing the same big picture), and that the divisions arose when people started reading the texts (and focusing on details of interpretation).
The essential elememts of many complex designs (of all kinds) can often best be described diagramatically e.g. buildings (plans, elevations, sections, perspectives), cars, electrical schematics etc.
It is surprising that this method of communicating the design of businesses and IT systems is often under valued.
IT must be the only complex design discipline in world that tries to communicate complex plans, designs, roadmaps etc. in a A4/Letter sized pages. In some absurd homage to Word (or similar document formats). Or in the futile attempt to pretend that these kinds documents are suited to communicating complex models, plans and designs (when their real strength is narrative i.e. they are good at telling stories)
The problem in this context i.e. complex design and planning is that there is an almost infinite number of possible stories (for different audiences, different perspectives etc.) and the underlying parameters change (albeit incrementally) - so any narrative ends up be at best partial and usually misleadingly or inaccurate.