This is arguable and Hickman had established in FF
ark Reign they are not a good idea every time they got involved things screw up. Shown by examples of alternate reality versions of them.
Which lead Reed to the right conclusion that the things they try to do are to big for them. For me this was only the half truth the other for me is they are not as heroes in this group.
You can say their error was the assumption that they are at the end of the food chain.
The other thing was out of TRO there were others who could give solutions until the end like Future Franklin and his planet phasing satellite or AIM Avengers planetary shield system.
On the other hand a cosmic version of the Illuminati would work like:
Cable(full power), Rachel Summer(full power), Jean Grey, Rick Jones(Destiny Power), Franklin Richards , Legion , Molecule Man(?), and Valeria Richards