If it’s not a famous book, you may find some Goodreads reviews and if you’re lucky a Reddit post or two, but not vasts amount of online discussion like you’ll find about any passingly good series or movie.
And if you love a movie or a tv show, it is much easier to convince people in real life to also watch it, since it’s way less time consuming and not everyone even reads books, but most people watch movies.
I just think that this really sucks about reading books.
Just like I don’t trust most movie reviewers analysis on what I would like, I don’t trust book reviewers. I have no problem going to the library, looking at the dust cover on 3 or 4 books and taking them home. If I find a book or two I don’t care for after reading a few pages, back it goes. I read what I like, not what someone else thinks I’ll like.