What? No I'm not. Literally no where has anyone said they've built a system with redundancies as recommended by AWS and still had problems.
Of course there are unacceptable failure rates. AWS doesn't have them, and pretending like they do is simply lying to yourself to protect your own ego.
Even when you're supposed to have redundancy, there are still certain failure rates that are acceptable and some that are not. And redundancy doesn't solve every problem either.