Maybe you don't print books at home, but the home publishing does exist. Mostly for small businesses who need to give each customer a slightly different book (if only because of updates). If you will sell 1000 books you should get a publisher to print the book, but if you are looking at only a couple per month print on demand at home makes sense as you can ensure everyone gets the latest corrections.

The above is moving to electronic, but paper still has advantages over electronics so it isn't dead.