Say the AI is in a Google research data centre, what can it do if countries cut off their internet connections at national borders? What can it do if people shut off their computers and phones? Instant and complete control over what, specifically? What can the AI do instantly about unbreakable encryption - if TLS1.3 can’t be easily broken only brute force with enough time, what can it do?
And why would it want complete control? It’s effectively an alien, it doesn’t have the human built in drive to gain power over others, it didn’t evolve in a dog-eat-dog environment. Superman doesn’t worry because nothing can harm Superman and an AI didn’t evolve seeing things die and fearing its death either.