Why does the USA seem particularly susceptible to regulatory capture and industry lobbying? Is it just money in politics or is something else happening?
When governing entities have limited money and power, they will need a lot of good will from the incumbents to have anything done at all.
The USA is at 38%. That's pretty low compared to most EU countries (e.g. France or Italy are at 58%), even lower than Brazil or Japan. And Japan has no offensive military to throw money at.
On an empirical basis, you'll find extreme examples of all situations, from full-on dictatures to company owned land masses. Whether it holds or not has to do with the specific country and its situation.
In a very real way, ideologies don't feed people, and usually it will be the reality of the country that nurtures appropriate philosophies, not the other way round (e.g. Chinese "communism" wouldn't have happened anywhere else, and you can't apply it to other countries willy nilly either)
Look how absurdly anti-union everyone is. That was a purposeful century of marketing by companies, and the US populous bought it without complaint.
Look at Citizens united and the absurd way people will twist very simple concepts just to ensure that corporations have MORE rights than people. We have no difficulty with limiting agents of the Government from doing things despite "the government" being made up of people just the same a corporations, but bad actors continue to insist we cannot disambiguate between an individual doing an individual act, and someone doing an act as an agent of say an LLC. Limiting a corporations speech does not limit the speech of individuals, only of agents of the corporation. You can say stuff as an individual that are illegal to say as an official entity of the org.