You are completely right Владимир, of course, as long as all you want is access. If you modify the text, and republish it on your own platform, then that isn’t the same book. It’s just the same text.
Think of that in real world terms, like you making a photocopied version of my book available. I don’t mind about the text being available or modified, I am however, interested in the abstract notion of ‘owning’ a ‘digital original’ non-tangible-artefact and transferring that ownership. Hope that helps.