Using brain spans to explain what makes code easy to read

I recently encountered a codebase astoundingly distant from this metric of readability. Even the simplest examination requires a fancy tool (IDE, or suitably configured editor) capable of jumping to function definitions across multiple repos (some private, some public). When I say 'fancy', I mean that I've never had to do that, because I was working on relatively-well-organized things in which an occasional invocation of grep would answer any question.

I feel fortunate to have never had to see such a thing until now, but it was a horrifying revelation: the system was not easily readable and understandable because it was built entirely with these fancy tools. The tools are no longer just handy productivity-enhancers. The system is incomprehensible without them. Some essential quality has been discarded to 'enable development velocity'.

I feel like a barefoot runner who can't run the race because the racetrack is covered in broken glass and the other runners are fine with this because they are wearing shoes. This is not ok.