I do not have any affiliation with Elevenlabs or OpenAI except as a user of their APIs. I'd actually prefer it if OpenAI had a better realtime product than Elevenlabs because it'd be more convenient.
FWIW I have no affiliation with any of these companies but I have a book coming out soon and have been researching AI audiobook tools and Elevenlabs seems to be far and away the consensus for that at least