> the code is only as good as its documentation

This heavily depends on your niche I think. If you're writing closed source vendor software and your client's only guiding light is your documentation, it's 100% true.

If you're working on a 5 people project that evolves at a fast pace, and everyone touching the code is expected to be familiar with the domain and operations, you'll mostly leave comments (todos, meta info, external ticket links etc), not documentation per se.

Everywhere I've worked, there is software written by those five people, who are now all rich and don't write code anymore, and I still would appreciate the courtesy of an explainer.

The trouble with good docs is that they are work to maintain, like good code. If we decide to change this component in a substantial way soon, which we likely will, I'd have to practically rewrite the docs! Why bother?

Because the docs are part of the code. Write the docs.

I don't expect to win this crusade, but I'll keep writing docs anyway. Then later people will modify the code without modifying the docs, and so the docs will be a lie, but still useful, I think.

It's like asking three people who are not closely familiar with a component, but who have worked with it, "what is this thing, how does it work?" You will get three different answers. It would be nice if one of them were a written description straight from the horse's mouth, even if the component is now more of a camel.