I think AWS should use, and provide as an offering to big customers, a Chaos Monkey tool that randomly brings down specific services in specific AZs. Example: DynamoDB is down in us-east-1b. IAM is down in us-west-2a.
Other AWS services should be able to survive this kind of interruption by rerouting requests to other AZs. Big company clients might also want to test against these kinds of scenarios.
I used to tell people there that my favorite development technique was to sit down and think about the system I wanted to build, then wait for it to be announced at that year's re:Invent. I called it "re:Invent and Simplify". "I" built my best stuff that way.
Other AWS services should be able to survive this kind of interruption by rerouting requests to other AZs. Big company clients might also want to test against these kinds of scenarios.