Reading code always felt awkward, slow and ineffective. The cognitive load is huge, you have to compute some things while memorizing others and at the same time keep track of flows. Thats why I always have pen and paper while diving into a new big code base, you simply can't keep it in your head. But something we forget often is... the goal of reading code is almost always to understand a system or some part of it. And reading code for me is a terrible way to do it.

Code is just one level of abstraction and one way of seeing things. We should have multiple ways of "reading" a system depending on what level we want to understand it. No, I don't think that rushed, out of date "system documentation" you wrote will do. I still think this is not solved in a satisfying way. We could find inspiration from things that works well, just imagine how google maps lets you look at the world at many different levels, from continents down to street level. Also it provides different views of each level, street maps are useful for tourists, terrain maps for hikers and satellite images for someone who want to study vegetation. How you will "read" a system depends on what you are trying to understand.