If you go far up enough the pyramid, there is always a single point of failure. Also, it's unlikely that 1) all regions have the same power company, 2) all of them are on the same payment schedule, 3) all of them would actually shut off a major customer at the same time without warning, so, in your specific example, things are probably fine.
No. It’s just that in my entire career when anyone claims that they have the perfect solution to a tough problem, it means either that they are selling something, or that they haven’t done their homework. Sometimes it’s both.
For what's left of your career: sometimes it's neither. You're confused, perfection? Where? A past employer, who I've deliberately not named, is selling something: I've moved on. Their cloud was designed with multiple-zone regions, and importantly, realizes the benefit: respects the boundaries. Amazon, and you, apparently have not.
Yes, everything has a weakness. Not every weakness is comparable to 'us-east-1'. Ours was billing/IAM. Guess what? They lived in several places with effective and routinely exercised redundancy. No single zone held this much influence. Service? Yes, that's why they span zones.
Said in the absolute kindest way: please fuck off. I have nothing to prove or, worse, sell. The businesses have done enough.
