Diagrams may not be necessary, but we all depend on auto-generated visualizations, whether it's a "find all references" feature of some IDE that produces a hype

Diagrams may not be necessary, but we all depend on auto-generated visualizations, whether it's a "find all references" feature of some IDE that produces a hyperlinked list, or in the most primitive case, the use of grep to produce a list of locations in files for some identifier. I'd argue that you need help if you're not using some auto-generated visualization to view relationships in code, because the alternative is to scan through files manually. The choice of diagrams, lists, or some other visualization is irrelevant, it's the preference of the programmer.