AWS is a prime example. EC2 unreliable, doesn't perform well and is expensive (and fairly weather dependent by the looks too). If you want anything that can actually shift anything, dedicated servers are cheaper (but you might actually have to commit - oh dear if your margin is that tight, you don't have a product worth it).

The only use case I can see for it really is rapid scaling but that seems only viable for content delivery as your data back end architecture is way harder to scale than click the magic cloud button. Back in the old days we used to do content via CDN (Akamai etc) which actually works out cheaper per GiB.

Then we approach things like S3 which is terribly unreliable (some of our clients use it for storage as it's cheaper than a SAN but they suffer for that). Drop outs, unreliable network requests, latency, rubbish throughput and buggy as fuck SDK.

Its like consuming value line products from a supermarket. Sure there's quantity but its lacking in quality.