>rather a unipolar world where one company, such as Google, reaps the benefits and determines the course of such an advance
Yes that is their model of AI risk. However the people worried about AI risk are not worried about any single organization controlling AI. They are worried about a world where no one controls AI.
Controlling AI is actually a very difficult and unsolved problem. OpenAI is not intended to solve that problem, and if anything they are making it far worse by accelerating AI research before the problem has been solved.