Cloud did bring with it the ability to quickly terminate an instance and no longer be billed for it. Renting equipment meant that equipment was your expense whether it was being used or not. So many people focus on cloud allowing one to scale up quickly, but to me being allowed to scale down just as quickly was the changer. Think of your local Target with 40 lanes of check out but with only 4 lanes open until the holidays where all 40 are open. During the remaining 10 months, they are stuck with unused square footage. That's what lease gear in your colo looks like to the bottom line.

The only thing that cloud brought is the possibility to spend less for smart people/companies that have the right workload. At the (hidden) expenses of the other clients that are not so smart or don't actually need that elasticity. Yes, there are economies of scale at AWS but in the end there is fixed capacity that either gets used or not.

Paying 2x as much per server means you need to drop well below half just to break even. But you always need a server or you can’t handle new requests. So at small scale there’s zero benefit from dynamic loads.