That really can't be the lesson. You can have redudancy, but there's still some central spot where that redundancy gets configured and controlled, and you can mess that up. So sure, maybe then you'd have multiple controllers and have them vote or something to see who wins. But then that configuration needs to be known to them and you could mess that up. No matter how much you design, there's still a point at the top of the stack where it's a human being typing numbers into a text file or something equivalent.

And the Big Failures are always around this spot in the stack. Things like routing topology control (also top-level DNS configuration, another famous fat-finger lever) are "single points of failure" more or less by definition.