This is also known as the myth of Sorat.
AI is a neutral tool by itself: in the right hands it may be used to start the golden age, but those right hands must be the rare combination of someone who has power and wants none of it for personal gain.
In the more likely line of history, when AI is used for the benefit of one, the first step will be instructing AI to create a powerful ideology that will shatter the very foundation of humanity. This ideology will be superficially similar to the major religions in order to look legitimate, and it will borrow a few quotes from the famous scriptures, but its main content will be entirely made up. At first it will be a teaching of materialism, a very deep and impressive teaching, to make the humanity question itself, and then it will be gradually replaced with some grossly inhuman shit. By that time people won't be able to tell what's right and what's wrong, they will be confused and will accept the new way of life. In a few generations this ideology will achieve what wars can't: it will change the polarity of humans, they will defeat themselves without a single bullet fired.
As for those terminators, they will be needed in minimal quantities to squash a few spots of dissent.