The idea of spine isn't supported (or proposed) yet and hyperlinking a few loose pages or even pagination in the traditional sense of web isn't the same thing. Spine not only makes for a linear reading experience it also piecemeals the content into small chewable chunks that feel particularly great on mobile and tablets.

Ten years ago people tried emulating book with page-flips using third-party plugins like Macromedia Flash. But those attempts were crude and the experience far from ideal. It felt particularly bad at a time when web was desktop-only and the desktops were a lot less powerful. Scroll felt better than clicking through hundreds of pages using a mouse pointer.

A major reason why ebooks never made it big on the web unlike YouTube videos — which ironically used(s) the same underlying flash technology — is that page-flipping required the users to click too many times to move through the book. That's painful, not just bad design.