A lot of the allstar PMs and Engs who helped actually GTM a lot of great Google products like Maps, Docs, Ads, etc left in the 2010s to start their own startups (eg. Jens Rasmussen - founded Google Maps and then left to found Where2), become execs at other companies (eg. Niklesh Arora @ PANW, Lars Rasmussen @ FB, Bret Taylor @ FB+Salesforce), become VCs (eg. Bret Taylor, Niklesh Arora), or (re)enter Academia (eg. John DeNero @ Cal).
There also was a change in how PMs began getting hired at Google in the 2010s when they brought a senior ex-McK TMT consultant to lead and revamp the Product team after Marissa Mayer left to become CEO of Yahoo.