Our book club has actually noted that more and more mainstream books are written for low attention span. Repeating details ad nauseum and simplifying the plot significantly. So I don't think books are immune to this automatically.
I've started avoiding many things created in 2023 or later - you can be pretty sure writing prior to that wasn't some AI slop someone threw together with a half-arsed prompt.
These days I have this vague paranoia that most of what I'm watching, listening to, interacting with is just the product of some meat proxy somewhere trying to put some more half baked crap in front of my eyeballs.
I wish I had a portal to human curated, absolutely non-AI, non-clickbait BS like the very old internet (which still wasn't perfect). I think that dream is effectively dead now. But old books/movies/music are still good. Now I sound like an old grandpa reminiscing about the old days.
I am not sure that that's recent. Most books, even before the internet, were kind of low-effort shit.
You've always had terrible borderline-porn romance novels at grocery stores and terrible pulp novels and the like. We just don't read terrible novels from 100 years ago; whatever we read from that era now has survived the test of time. The same cannot be said about anything released in the last couple years.