it's fascinating to me how much the reddit bookbinding community focuses on rebinding extant books, as the default kind of bookbinding they do. I'm so used to the fandom approach, which is to start from making a typeset! I suppose the difference comes from whether the e-text of the work you want to bind is freely available or not? but even then, if I wanted a nicely hand-bound copy of a professionally published book, I'd almost certainly be taking an epub and stripping the text out of it to serve as the basis for making my own typeset!