In our case this is mapping. Generally I see that we only need 1 map app, and that each slice of data should just be a layer for that map. This is the way I would've traditionally done it, and it's the way that I think is 'right'.
However people seem to search not for layers on an app but for a specific app that fills their very specific needs. An app that shows them locations of ATMs is more discoverable and useful to them than a plugin to a different app that supplies a layer to the generic mapping app.
People seem to prefer to have one app that does one thing well and does nothing more. Even if this means that they end up with 50 such apps on their device and a lot of functionality is duplicated in several of their apps (with mildly inconsistent UI).
So we're seeing in our own apps that multiple apps dealing with one small thing is more successful than fewer apps able to deal with multiple pieces of functionality.
Going back to your example, I'd rather have a Gutenberg app that allowed me to grab the books I wanted, but I suspect you'd see more success having apps that match how people would search for them, which I bet would be by author... a "Philip K. Dick compendium" for example and then a "James Joyce compendium", etc.
I still prefer the fewer richer apps, but I seem to be in a minority.