How so? AI is not smarter than people.
Even when it becomes smarter than humans in the future, I would still oppose this idea. We humans have seemingly benevolent leaders who become malevolent. At least we can replace them as they are around as smart as us. A malevolent creature that is waaay smarter than us that rules over us? No thanks.
The integrity of blockchains isn't immune from malicious activity. It is just way way harder to be manipulated. No blockchain means 1 server needs to be manipulated. Blockchain means more than 1 servers need to be manipulated.