Yeah the documentation (if it even exists) of most projects is usually clearly written by people intimately familiar with the project and then never reviewed to make sure it makes sense for people unfamiliar with it. But writing good detailed documentation is also really hard, especially for a specialist because many nontrivial things are trivial to them and they believe what they’re writing is thorough and well explained even though it actually isn’t.

I write technical documentation and training materials as part of my job, and the state of most open source documentation makes me want to stab people with an ice pick.