That's what technical reviewers do. I did it back in the early 2000s. You get sent a copy of a few chapters, and it's your job to review the code and explanations to find errors. It doesn't pay very well though - you get your name in the front, and a free copy of the book, but nothing much else.
So now my name is attached to incorrect information, and occasionally someone will message me and tell me why I was wrong and I have to message them back and say, "well I told them to fix it but they ignored me".
Well... in theory they should be. I published a book a while back through a publisher, and they assigned me a copy editor and a technical editor. The copy editor was amazing - it was clear she didn't understand any of the technical details, but she spotted flow errors and minor grammatical mistakes in dense technical prose. The technical editor, on the other hand, seemed to have (maybe) skimmed over the content and his only feedback was that he didn't like my writing style very much and left it up to me to verify all of the technical content. I did take it seriously, though, and I am proud to say that very few technical errors have been reported.
Not to replace human review but should catch a lot of mistakes
Depends upon the publisher too, whether they are interested in publishing quality books or have a quantity policy.
>We all make errors, even those of us who do know what we're talking about
I was hesitant to write a book for a long time because I thought I wasn't good enough. I still think I have a long way to go, but I've grown better as a writer with experience. Feedback from users have caught many issues and helped me improve the content.
And it was out of date very quickly.
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.
This is why I'd be very hesitant to self-publish a technical book, even though for fiction I think self-publishing is the right decision 99% of the time. We all make errors, even those of us who do know what we're talking about, when you get to the scale of 100+ kilowords. For a novel, a decent copyeditor can fix up the production values well enough; for a technical work, you would hope the publisher assigned some people to check the work.