I still have yet to see a plausible, step-by-step example of how this hypothetical AI manages to grab the levers of real-world machinery, factories, industries, raw material excavation, etc, and causes mayhem.
Think of the havoc government intelligence agencies are rumored to be capable of, in terms of hacking vital infrastructure. Or even all the ransomware outages.
Now imagine super human computers performing the same kind of attacks.