Scaling of training was the challenge back then (of course).
Google was already too corporate. Please remember that Sergey Brin and Larry Page were no longer at the steering wheel back then. I have been told that it was also a cultural issue linked to "delivering brilliance". Simplifying: Google promoted tiny teams or individual contributors building things that had to become a massive success quickly. Open AI took a number of hand picked brilliant people and let them work together on a common goal, silently, for quite some time.
Some companies just have an unfair advantage. A certain magic. And OpenAI's magic is at risk right now.