Sure it is. So is writing good code too. Good quality human work is quite often expensive. But code and docimention are tied up together, and documention starts to be expensive at that point when no one does it. Otherwise it is just cruicial part of a product as is coding including testing, design, UX/UI etc. But devs quite often hates documentation because they just hate to do it, there is noting sexy in it, plus they are quite often really bad at it 
But because owners of companies, and other supervisor, are similar devs they just don’t care that guys are cherry picking what they do, and don’t do.
But now I’m drifting to too general things that are way too much off topic. So I’ll off and pointing to Documentation because it is evolving right now.