Google's executive leadership team in the late 2000s to early 2010s famously consisted of a number of very strong and ambitious personalities. Amit Singhal ran Search Eng; Marissa Mayer ran Search PM/UX; the two of them famously did not get along, to the point where they would actively undermine each others' decisions. Alan Eustace was over them and often responsible for mediating, but he was close to retirement (which he later did to set the world record for highest skydive [1]). Sundar started by running the Google Toolbar efforts and then Chrome. Andy Rubin was in charge of Android. Urs seemed content to run hardware and datacenter ops; he's one of the non-combative ones, and is still there now though he's semi-retired. Likewise with Susan Wojcicki and Ads. Milo Medin had been brought in from Excite@Home to lead Google Fiber. Sebastian Thrun and Anthony Levandowski had been brought in from acquisitions to form Google Chauffeur (now Waymo).

Over the 5 years between 2010-2015, the search PM/TLM org chain basically revolted and said "We can't get anything done when Marissa tells us to do it one way and Amit says no, we have to do it another way". Marissa was moved to run Geo and then eventually left to become CEO of Yahoo. Amit himself got canned over a few sexual harassment complaints. Alan Eustace retired, as everyone expected. Andy Rubin made some ill-faited acquisitions of Motorola and Boston Dynamics that lost him a lot of cred, and then the nail in his coffin was when the media discovered his sex dungeon [2][3]. GFiber failed to gain significant traction, so Milo wasn't really a viable successor candidate (arguably he wasn't really in the running, and was there just to run Google's ISP ambitions). Anthony Levandowski stole Google's trade secrets on self-driving cars and sold them to Uber; he was criminally convicted for this but was pardoned by President Trump and is now founding a religion [4]. Sebastion Thrun left to found Udacity.

Sundar, meanwhile, steadily delivered on Toolbar, and then Chrome, and then took over Android when Andy Rubin was ousted, and steadily improved Android as well. He was unremarkable on the product front, but had a reputation as a peacemaker among Google's more volatile execs, as well as a very good translator of Larry's brilliant ideas into terms that mere mortals could understand. When he became CEO, it wasn't because he was remarkable, but because he was unremarkable enough to manage a number of remarkable personalities that had the egos to go along with it.

[1] https://en.wikipedia.org/wiki/Alan_Eustace#Stratosphere_jump

[2] https://www.cbsnews.com/news/google-paid-35million-former-ex...

[3] https://mashable.com/article/andy-rubin-sex-ring-court-docs

[4] https://en.wikipedia.org/wiki/Anthony_Levandowski#Criminal_c...