One reason is because I feel like I actually don't read that many books.
And I feel like I end up recommending almost only mainstream ones.
I might kinda be comparing myself to those booktubers, who seem to be very good at them (and also the oddly specific recommendations).
Like if someone asked for a horror book recommendation, I would say "Dr. Jekyll and Mr. Hyde" because that is almost the only horror book that I can think of.
And I would suck at the oddly specific ones that are like "A book recommendation for a cat lady, who enjoys playing chess and watching French movies" (very random example)
And I would be like "Alice in Wonderland & Through the Looking Glass" because of Chesire cat, the chess references in TTLG, and the parts of AIW where Alice is speaking French.
I was also thinking about the book "The Queen's Gambit" by Waler Tevis just because of the chess thing, but I haven't read that book.
But some booktuber would probably recommend some unknown book that might fit the description better. Perhaps some book translated from French, which is about a chess player living in Paris with her cat.