The thing is that they, like state and local prosecutors, prosecute poor people who can’t afford effective representation tens if not hundreds of times as often.
If you isolate their stats with regards to rich and/or powerful defendants like the Mango Mussolini, suddenly they don’t convict at anywhere near that rate.
The difference is so immense that even an obviously guilty oaf with incompetent and unhinged lawyers like him is more likely than not to win or at the very least delay until his own death at his country club home.