Obviously Eric wasn't creating the inventions himself, but I would argue that he fostered innovation very effectively in the way he ran the company. Eric hired amazing people and put them into an environment where bottom-up innovation could happen, and then he stood back and let it happen. It was chaotic, but a lot of great stuff came out of it.
OTOH, when Larry took over, things became much more top-down, with Larry trying to be Steve Jobs and tell the company what they should be building next -- most notably when it came to Google+.
I left before Sundar took over so I don't know how he runs things, but it seems like Google these days is just sort of chugging along, building solid products but not doing anything revolutionary.