This is not a provider scarcity problem - there are numerous providers out there, but user's problem - they voluntarily choose crappy service at large scale, believing sales managers "it's reliable".
Terms like reliability have specific definitions in computer systems:
Term | Definition | Measurement
-------------- ----------------------------------- -------------------------------------------
Availability | Basically, system uptime | A percentage over time
Durability | Basically, persistence of data | A percentage over time
Resiliency | Basically, self-healing | A probability within a time period (usually)
Reliability | Basically, operational probability | A probability within a time period (usually)
Fault tolerant | Basically, it cannot fail | Binary (it has faults or it doesn't)
Unlike more mathy fields, reliability is more of a "quality" that is qualified by one or more measurements (like Mean Time Between Failure). You define your metric, you give an estimate of what that value should be, and if you come in under it, you're reliable.
AWS has always stretched the truth when it comes to these numbers, but they do come pretty close to them most of the time. If you can find a different provider who'll even offer a number, it is usually not as close, and there's usually no contract that has any teeth to enforce it. Or they'll give very vague claims that don't get into specifics.
At least, not for "cloud providers" (other than the hyperscalers). You can find a datacenter who'll give you a number, but that's for like, their power reliability. That's a very different thing than saying "there is X probability over Y time that a server I run for you will not go down". Partly because it's pretty freakin' hard to wrangle all the different things that can go wrong with so much certainty that you can put a number on it. So most people give things like reliability, durability, availability, etc numbers for specific components of a system.
AWS S3 offers 99.999999999% durability and 99.99% availability. Now, did AWS S3 go down completely during the outage? Not as far as I'm aware. Maybe the control plane did, or a management portal, or billing, or something? But I'll bet you the PUT, GET, DELETE operations kept on flowing within 99.99% availability. Some other components in AWS may have been failing like crazy (which may have no guarantees...), but that one component probably stayed up within its guaranteed amount.
Design your apps to run on AWS using the components with specific guarantees, and you can estimate how reliable your end product will be. As far as I know, nobody has a better track record for meeting the guarantees. Even considering events like this.
