I once was contacted by a technical book publisher, known for producing a lot of so-so books on specific topics, to be a reviewer for a book on then-hot technology. The book was technically OK, but was put together in such a disorganized and sloppy way that it was a hard slog to look through it. As a reference text, it would have been ok had it been organized as such. This was before stackoverflow, but you could make the same book today by scraping all the stackoverflow questions and answers on a topic, throwing them together and calling it a day.
This is a problem with "then-hot" technologies. A number of years back, I was approached by a technical publisher to do a book on OpenStack. I wasn't the right person anyway and passed. But even if I had been, by the time a book would have realistically gotten to market, say 12-18 months, it would have been 3 versions back of the current project.
And it was out of date very quickly.