You may not have noticed the 2x multi-hour outages Salesforce has had in the past 2 weeks, at least one due to "power problems", the more recent of which took down their fucking status site too.
My point wasn't that Salesforce's infrastructure is reliable (although they arguably have more pressure than most companies to be so), just that there is a separate resource they could be utilizing as a backup/in addition to AWS that they currently are not using.
Presumably if they were having to deal with a power outage you could reliably assume that that fucking status was set to "not fucking"