I would say are outside of D&D but that’s why you should play pf2e instead and here’s why *rimshotThat's not surprising. RPGs are (were?) an incredibly niche hobby. Most fantasy and sci-fi fans are voracious readers. Taking a chance on a novel is no risk at all. Worst case you're out a few bucks and you read a terrible book which you can trade to someone else for something you might like.