Nobody except newcomers to the codebase look at documents on code structure, and of course no one is fired for not producing it/producing a crappy version of it

Nobody except newcomers to the codebase look at documents on code structure, and of course no one is fired for not producing it/producing a crappy version of it. When the newcomer can't get anything out of that doc, if it exist, he/she just need to ask the creator, who will explain very nicely how everything is done, and that newcomer become a code guru in that codebase, and the cycle continues. Until you layoff 50% of the team and now suddenly nobody knows how 50% of the stuff work.