Earlier quoted context omitted.
I think Nadella is a clear case of MS getting lucky. They picked a leader from their own ranks that transformed the company in a few short years. Given the names that were circulating for that role at the time, I don't think they could have done better. It's current valuation would not have happened ever under Balmer. Not even close. That's why he was pushed out. MS was down a path of slow decline and now they are no…
I think the decline of Microsoft in the mid-2000's was mainly caused by them missing the boat on the two massive shifts in computing -- from desktop software to web and mobile. Google, on the other hand, is firmly entrenched in both web and mobile. Until there is a similar shift (if there will ever be one), I don't see Google stagnating the same way that Microsoft did.
Google at the same time seems to struggle to convince developers that they need to drop their fancy languages for a bastardized and outdated thing called Dart that basically can only be explained as a ginormous not invented here syndrome combined with sunk cost fallacy. Just a minor example of things Google tries that have an obvious ticking clock in terms of them killing it in favor of something else. Also what's up with having 3 operating systems for devices and dragging out picking one out for half a decade? That's Conway's law in action right there.