Have you tried looking? There's LibraryThing and a couple others.
I don't think there's much value left on the table in the niche, though. Kindles have first-class Goodreads sync and even a Goodreads button in their global navbar. And Goodreads' competitors, for the few people who don't want to use Goodreads, already have a deep rut of incumbency.
Even you, who has supposed great issues with Goodreads, apparently wasn't bothered enough to even see if competitors existed all this time, much less before writing your comment. Doesn't bode well for the Goodreads' competitor market, lol.
Reddit has terrible search too, but you can appreciate that "Reddit but with good search" isn't all it takes to compete with Reddit. That's 0.001% of the work.
And of course Goodreads has issues of its own, but none of them are show-stoppers for most people, especially few of the people who just use it as a glorified Excel spreadsheet.
I only chuckle about this because, like many enterprising HNers, I myself have considered building a Goodreads competitor in the past and even managed to build the ol' weekend prototype (i.e. 0.001% of the work). It's one of those projects where you start and, after you get some of the easy things done like fuzzy search, you go "wait, wtf am I doing? Who would switch to this?"
Using and improving OpenLibrary is also alluring, but pretty hard to do without an application with actual users that have some sort of "edit book" functionality that you can then moderate and submit upstream to the OpenLibrary data source.
I think most people use Reddit to just browse the subreddits. GoodReads is about searching for books an adding then to your shelves, many of those might be books that someone just mentioned to you in passing, or you don't remember the full/correct name.
I don't think there's much value left on the table in the niche, though. Kindles have first-class Goodreads sync and even a Goodreads button in their global navbar. And Goodreads' competitors, for the few people who don't want to use Goodreads, already have a deep rut of incumbency.
Even you, who has supposed great issues with Goodreads, apparently wasn't bothered enough to even see if competitors existed all this time, much less before writing your comment. Doesn't bode well for the Goodreads' competitor market, lol.