>It is an interesting conundrum though, what if all your nearby availability zones come down at once due to power loss? I wonder which major cloud provider has the best setup for these sort of events

im only familiar with microsoft in this sense, but they have "geo-zone-redundant storage" which copies data across 3+ availability zones in the primary region, and also a secondary geographic region (i think at least 100 miles away if i remember, but maybe further). any incident would have to be massive to affect multiple geo-zones