Sergey might have some positive influence on Gemini, but given that he isn't an AI scientist ( AKA no technical background), I really do wonder what sort of influence that (only) he could have had, beyond just bringing in key people.
He's probably not developing the low-level algorithms but he can probably do everything else and has years of experience doing so.
He's also perfectly able to spend 60 hours a week improving his AI skills using the best teachers in the world.
I also think this doesn't make sense, because he certainly stayed on top of things