"It's complicated"

Having been in Amazon, Google, MS, the Google process is (was!) a clear outlier, which was totally culturally aligned with how everything else in the company worked.

1) Designed to fail closed
2) Detail over big picture
3) Written over relationship

1) "Fail closed" -- jargon for "optimised to say no by default".

Many processes in Google were like this, probably the largest other one being the hiring process. (Many Googlers hated the hiring process since they felt it said no to people who would 100% have been great hires...

...sometimes being burned to the extent of refusing to do any more interviewing.)

But the promotion process is (was) the same way - if the committee couldn't convince itself the case was watertight, it wouldn't promote.