They don’t get updated with the latest emotional hot button issues so they just can’t stomp on emotional triggers as well. It’s much easier to digest arguments and see the errors when you can reread them. They don’t take long to read so they don’t clog up access to other sources.
Rebuttals are targeting a specific argument so you can’t just keep throwing up intellectual chaff.
I read Atlas Shrugged as an impressionable young teen, and developed some pretty horrible notions about society and morality (and literary technique) as a result. Of course I saw the error of my ways, in no small part by reading other books!
Don't get me wrong, books-as-propaganda isn't necessarily bad. Animal Farm, 1984, To Kill a Mockingbird... These are brilliant but are also such effective forms of propaganda that even mentioning their titles is a form of propaganda in itself.
I think that shows their weaknesses. Propaganda seems to work best when reinforced over long periods. People read a book and get really into something for a while, X is now the one true diet! However, I rarely see longer term shifts without something else reinforcing the ideas.
By comparison the US military has been subsidizing media who want access to military hardware for decades as long as they follow a few guidelines. It’s a subtle drip of propaganda but across America and much of the globe people’s perception has very much been influenced in an enduring fashion. No single episode of talk radio or Fox News is particularly effective but listen for years and you get a meaningful effect.
I would be more worried about you developing a terrible sense of narrative and character development. I would kill for a well written ancap paradise book (there are plenty of Ancom options) but it honestly just sucks as a piece of writing I cant get into it.
In my experience, consumers of propaganda respond to emotional and social cues. They rarely ever review the information provided without social and emotional context. Its always a video or a rally or something.