I remember there were multiple such websites before being shared in HN. I bookmarked them, and a couple years later when I finally wanted to find a book, the only thing I got is 404.
I hope this one lives longer.
https://news.ycombinator.com/item?id=2249390
I planned to revive it later, but life got in the way
The book recommendation aggregation website is so common because it’s one of the few variations of this theme that can be monetized through affiliate links.
None of them last long because the traffic falls to zero basically as soon as it falls off the front page.