OpenAI is currently selected for the brightest and young excited minds, (and a lot of money).. bright, young (as in full of energy) and excited people will work well anywhere- esp if given a fair amount of autonomy.
Young people talking about how hard they worked is not a sign of a great corp culture, just a sign that they are in the super excited stage of their careers
In the long run who knows, I tend to view these companies as groups of like minded people and groups of people change and the dynamic changees overnight -so if they can sustain that culture sure, but who knows..