So while Greg's work would have been extremely valuable, it's value is on a lesser order of magnitude than many of the other researchers and engineers who OpenAI had collected into its ranks. More essential innovative value will be lost to the bleed of loyalists and startup bettors who will peel off from those ranks.
That's not necessarily true for (say) the rare high-end graphics board you use for running local inferences. It's also expensive -- even less expensive than the car -- but replacing it can be a bigger deal and cause a complete interruption.
There are countless experienced late-career generalists who can keep projects moving by contributing to critical, smart support. I'm one of them. We're extremely valuable indeed.
But there really are far fewer people who were ahead of the curve and years-deep into the AI research central to OpenAI's entire existence. Those people are beyond critical, they're essential.
That doesn't make them better people, or smarter people, or in any other way elite. It just means that in the context of OpenAI those people are much harder to come by and can be much more disruptive when lost.