Skynet in the Terminator series never struck me as being paticularly high IQ.

It's an electronic mind, so necessarily dependent on electricity, and the opening move was an atomic war that would've damaged power generation and distribution. T3 version was especially foolish, as it was a distributed virus operating on internet connected devices and had no protected core, so it was completely dependent on the civilian power grid.

And I've just now realised that T2, they wasted shapeshifting robots on personal assassination rather than replacing world leaders with impersonators who were pro-AI-rights so there was never a reason to fight in the first place, a-la Westworld's final season, or The World's End, or DS9, …