I'm pretty certain that that's a misunderstanding, and rollouts at Google still happen faster than at most other companies incl small & mid size. It's just that Google won't rollout to the whole world in one instant step, instead, it depends: can be hours, days or weeks. Or sometimes a first small step during less than a minute, and then a more large scale deployment — e.g. if there's an urgent security bugfix. It's in the SRE book (well as far as I remember), I think you'll find it if you search for "seconds" or "minutes"

https://static.googleusercontent.com/media/sre.google/en//st...

But yes definitely there are other things that slow down big companies.