I agree that we should be reading books with our eyes and that feeding a book into an LLM doesn't constitute reading it and confers few of the same benefits.

But this thing isn't (so far as I can tell) even slightly proposing that we feed books into an LLM instead of reading them. It looks to me more like a discovery mechanism: you run this thing, it shows you some possible links between books, and maybe you think "hmm, that little snippet seems well written" or "well, I enjoyed book X, let's give book Y a try" or whatever.

I don't think it would work particularly well for me; I'd want longer excerpts to get a sense of whether a book is interesting, and "contains a fragment that has some semantic connection with a fragment of a book I liked" doesn't feel like enough recommendation. Maybe it is indeed a huge waste of time. But if it is, it isn't because it's encouraging people to substitute LLM use for reading.