That's because those books (very popular in airports) are blog posts extended out into books with almost no value add as a result aside from some "choice" anecdotes intended to prove whatever points they're making. Usually it's the same point people have been making for 4+ decades. The act of reading books like those, deciding to read a self-help book for example, is almost more important than whichever book you pick. Most of them are interchangeable. They're meant to make you think you're improving yourself by reading them. (Dalio is more trying to position himself as master of the universe.)
Actual academic monographs and good novels are usually book length because their arguments and stories (and characters) require that book length to reach their full potential.
Yeah, taking those as one's examples is the equivalent of judging the medium of film by watching YouTube "brain rot" videos. "These were a waste of time and I didn't get anything out of them". Well, yeah. That entire genre (I'm back to treating of self-help and pop-business and "surprising" pop-science books) is infamous for being all but entirely garbage, defying Sturgeon's usual "90% of everything is crap" and achieving something more like 99.9%—and even that may be a generous assessment.
I'd be intrigued to hear the argument fully flushed out for once. The Dalio worship after the "principles" exposés is baffling but at the same time he does appear objectively successful.
I think his game is no longer about developing analytical skill to be the best investor, but becoming the person who has access to high level people and gets actionable information on an international scale before others.
Actual academic monographs and good novels are usually book length because their arguments and stories (and characters) require that book length to reach their full potential.