Interesting theory. I'd venture that there is an element of selection happening though rather than just a structural flaw. i.e. The people aren't so much trapped in this captured market but rather actively opt in.
I believe you would be right. The structural case is made in Network Propaganda. One of the authors has another paper/article (1) that summarizes this and supports your point. I don’t see any sustainable future for America, or any other nation, unless this market is rebuilt.
To argue the case - while there is definitely an aspect of choice, opt-in matters less if your options are limited.
