"AI is “stateless” in an important way, even with its context windows. It can infer why something may have been written in a particular way, but it (currently) does not have access to the actual/point-in-time reasoning the way an actual engineer/maintainer would."

CoT fixes this. And in a way, non CoT can retrigger its context by reading the code.

In a similar fashion, engineers remember their context when reading code, not necessarily by keeping it all in their head