As far as I can disentangle from [1], OpenAI posits only moderate superhuman performance. The profit would come from a variant where OpenAI subsumes much but not all of the economy and does not bring things to post-scarcity. The nonprofit would take ownership of almost all of the generated wealth, but the investments would still have value since the traditional ownership structure might be left intact.

I don't buy the idea myself, but I could be misinterpreting.

[1] https://blog.gregbrockman.com/the-openai-mission