Anime gets people started, then they start reading other things from Japan. The west doesn't have such a pipeline to make casual persons into readers.

Edit: Anyway, the culture of celebrating authors in general rather than trying to create franchises helps a lot for all sorts of books.

No, I don't think somebody getting into Re-Zero is going to start reading VNs like Umineko someday, let alone progress to literature, in the same way as how somebody watching the MCU is unlikely to progress to Infinite Jest.

Geographical distinctions don't really make sense in deciding preference, you start with genre elements and pick from there, regardless if it's Western or Japanese. Ignoring a work because it comes from X country would just be bizarre. As a sci-fi or fantasy fan I don't make distinctions between Japanese or Korean or Western works, nor do I see other fans doing so. For example, I wouldn't be comparing Satoshi Hase's Beatless in the context of "Japanese" works, I'd be comparing it to other AI works. The only limiting factor is translation.

But cross-genre pollination doesn't really happen nowadays, most shounen readers will never go or even avoid mecha, and so forth. Otaku culture especially is much more fragmented today than in the early 2010s.