The high-revenue, low-accountability political-industrial machine is free to go about its business whether or not it is solving problems for the American people, as long as alternatives are kept out.
The votes are essentially already counted (In a duopoly, you don't get to choose what you'd LIKE), which frees the political-industrial complex to focus on other, non-voter customers (The duopoly's true target customers are not the American people).
Ref:
who does a calcified political duopoly benefit? well, the two parties, for sure - since they don’t have to compete with anyone(The duopoly works well together to insure competition is kept out) nor serve the public (the political machine is not a public institution). but also the-state itself, since The duopoly can ignore the American people while keeping them happy even though Most Americans are unhappy with the services rendered by the government..
Because The duopoly can ignore the American people, the parties can structure their rivalry in a way that benefits themselves, as institutions, and are not pressured to structure themselves in a way that would benefit the public interest (The duopoly's true target customers are not the American people).
As long as alternatives are kept out (The duopoly works well together to insure competition is kept out), The duopoly can ignore the American people.