Right.
let us get some things straight.
The illuminati made one major, humongous, ungodly fuckup, all others being irrelevant.
They told Vic to get bent.
Fact is that, the way the story was structured, several elements were needed for Vic, our true god and savior, to carry out his/MM's plan. These elements, chiefly, were:
1. Tchalla accidentally stumbling upon an incursion.
2. Steve stopping the Builder Armada.
3. Illuminati building the bombs.
4. Namor actually using the bombs.
That they mindwiped Steve is irrelevant, he'd actively antagonize the other points. That they built the bombs is irrelevant, they needed to be built. That Namor had the balls to use the bombs is irrelevant, 616 would've died sooner if he hadn't AND he got UN backing for their continued use (at which point steve also got told to get bent by the whole world).
One should keep in mind that the reason the rest of the world were hunting the illuminati wasn't because they saved za worudo, but because they were trying to stop the cabal.
Oh but the Cabal was cruel and whatever the fuck. Yes, and they did what needed to be done. In order to save trillions, they actively killed hundreds or thousands. Aside from the people on the earths that they personally murdered, Thanos, Namor and company have saved more people (or prolonged their life) than any other characters in the history of Marvel and unwittingly ensured that some form of reality could be saved.
Vic needed the extra time afforded by the incursions, and used it well. Every player in the illuminati did a lot to ensure that. Every player in the Cabal did a lot to ensure that. Every single incursion that 616 faced mattered.
No one gets to judge the Cabal. They went public, got support, and did what they had to do. With sprinkles on top, since you might as well enjoy your work.