It's salient that the video is from 2010. Where I was (not Google), the push to make everything multi-region only really started in, maybe, 2011 or 2012. And, for a long time, making services multi-region actually
was a huge pain. (Exception: there was a way to have lambda-like code with access to a global eventually-consistent DB.)
The point is that we made it easier. By the time I left, things were basically just multi-region by default. (To be sure, there were still sharp edges. Services which needed to store data (like, databases) were a nightmare to manage. Services which needed to be in the same region specific instances of other services, e.g. something which wanted to be running in the same region as wherever the master shard of its database was running, were another nasty case.)
The point was that every services was expected to be multi-region, which was enforced by regular fire drills, and if you didn't have a pretty darn good story about why regular announced downtime was fine, people would be asking serious questions.
And anything external going down for more than a minute or two (e.g. for a failover) would be inexcusable. Especially for something like a bloody login page.