At least IL AGs havent been dumb enough to do this. They know if they go national, the corruption will be exposed and they'll go to jail. Typically, if they keep the corruption in state, they can get away with it. We, the people of Illinois, have largely become desensitized to corruption and has become a running joke. I mean, something like 6 or 7 of our last 11 governors have served time for corruption, and that spans both parties.
Or perhaps they are active against multinational corporations but arent physically close enough to the media for it to ever surface?
Then, it's simply a matter of experience: corporate and especially financial law is beyond complex, and they have the expertise, plus the financial resources, to investigate such cases. New York law is also similarly ahead.
And, of course, the majority of Attorneys General are currently Republican and have absolutely no interest interfering with corporations unless those happen to be involved in journalism, renewable energy or other despicably altruistic lines of business.
The parts that are not functioning are the legislature and executive branch.