Weirdly, I mind the CIA the least out of all of them. They are pretty good at staying outward facing. They 100% do fucked up shit and can't stop terrorism to save people's life, but in terms of hunting down terrorists afterwards or just fucking over another country, they are the best available. Also, them stopping terrorism once the target entered the US really isn't their job.
I don't believe that they had knowledge of 9/11 or what was going to happen. They definitely armed Osama before and enabled the rise of Al-Qaeda, but that was a risk taken that paid off, as it directly contributed to the fall of the Soviet Union, but they thought that they could get away clean. Osama was wanted after the World Trade Center bombing. They had a chance to get him around then, but the Clintons said no.
It's the other ones I hate more. The NSA constantly spies on us. The FBI likely caused the OK City Bombing to cover for the ATF's fuck ups at Ruby Ridge and Waco. The FBI is the most corrupt IMO, with their inwardly
I will give a little credit where credit is due, the FBI is the reason we don't have domestic terrorist networks. Their informant program (they are the actual glowies, tbc) means they've infiltrated every group that's vaguely suspicious. And they glow in the dark on purpose: that someone proposing violence is called a fed is a victory for the FBI. The issue with Antifa is that they are very decentralized, and so hard to infiltrate, as they learned from the soviets. Also, the US gov didn't care about infiltrating them until recently, then Biden clamped down on that. But it's important to understand that they use this good to justify so much bad.