> Complex society is a potent counterargument to this hypothesis.

Complex society is the demonstration of that hypothesis. Misaligned incentives are widespread and corruption and inefficiency are the result.

> Systems that rely on good people to work are fundamentally flawed. Instead, the game has to be about aligning self interets in favour of the collective.

But now you're making a different argument.

"The enemy of my enemy is my friend" works by random chance. When Evil Corp pays off Candidate A and Pollution Inc pays off Candidate B and then it's Candidate B who gets in and retaliates against Evil Corp for backing the wrong horse, you're getting a good result by chance rather than by design. All it would have taken was for Candidate A to make a better prediction about whether they need to bend the knee to Pollution Inc too in order to win and the same system produces something even worse.

How to actually get their incentives to align is an extremely unsolved problem. The best method we know if is to subject them to competition, e.g. break up concentrated markets and place strong limits on what lawmaking can happen centrally, leaving everything possible to state and local governments while allowing people free choice in where they live, so that no one is forced to stay in the jurisdictions that make the worst choices. But the forces of corruption want the exact opposite of that, and have been gaining ground.