Pichai spent all his management career at Google. He is undoubtedly a very bright individual but his personal life experience is limited to a single company which was on the rise during his entire career. He came to prominence by inventing the MSIE Toolbar. The thing was quite insidious: when installed, it showed some proxy for the PageRank of the current page (not the real PR). That gave it a reason to call home for every visited page -- this data was used to improve search quality. In addition it distributed Google Search to IE users. Toolbar generated some billions of dollars for Google. Pichai was also instrumental for starting the Chrome project.
Pichai is an extremely shrewd politician. An excellent diplomat. He manages the company by finding the balance between internal power groups. When the company is growing that's all that is needed. That's absolutely not enough when things go sour.
Here is an example. Google Cloud is failing. The fundamental reason for the failure is quite obvious: the margins in the cloud business are much smaller than in the ads/search. Consequently it's starved of good people. After all, if you are in sales why would you work on something which has 5 or 10% margin when you can work on something with 30 or 50% margin? The solution to the problem is also simple -- spin cloud off into a separate business. But that requires splitting up Google's infrastructure. That means a conflict with Urs Hoelzle. Which is impossible for Pichai. He would rather see Google Cloud die than pick a fight with a powerful old-timer like Urs.
That brings me to the Google culture at the top. If you want to have a career at Google you need to do something visible. At the lower levels it means working on a new project. At a VP level you need to start a new audacious project (this is why Google has 6 instant messengers). If it launches you get recognition and money. If not your career slows for a year then you do it again. Once launched, the project is no longer relevant for the career and can be passed to someone else for maintenance where it's starved of resources and slowly killed. This culture was formed long time ago, under Schmidt and Page. Pichai just perpetuated it. As long as ads and search generate healthy amounts of cash this may continue indefinitely. At the same time the new challenges and the new markets are likely to be missed by Google, just like it happened under Balmer at MSFT.
Pichai is status quo.