It's not interesting. You can regard OpenAI as one of the most prestigious AI labs in the world and only the best of the best get a chance to work there.
It’s very interesting that you think most people with a PhD working in AI / ML / Data Science academically can’t get a job at OpenAI.
You can easily see a lot of people who work at OpenAI on LinkedIn. University AI labs are always left out because non-commercial products just aren’t as noticeable.
I highly doubt that many of these academics would struggle being amount candidates at DeepMind, OpenAI and FAIR.
Prestige is very subjective, which makes it also very broad thankfully.