I think the QPS dream is something that was teased at to show feasibility (and scaling up services on the cloud IS simple when needed).
I think the bread and butter for the big clouds however are customers like the shop I'm at (see sibling comment), we can do development work and put it on our clients (mostly non-IT that has no interesting in hiring their own department) and if we for some reason need to part ways it's easy to "hand-over-the-keys" since subscriptions can be handed over between organizations.
But getting customers back is usually equally easy since there was never any fuzz when leaving so when they've become dissatisfied with the "cheap" options they don't remember leaving being a problem, regardless the winner is the cloud provider (but the costs are still small enough for each client that nobody is unhappy).
I think the bread and butter for the big clouds however are customers like the shop I'm at (see sibling comment), we can do development work and put it on our clients (mostly non-IT that has no interesting in hiring their own department) and if we for some reason need to part ways it's easy to "hand-over-the-keys" since subscriptions can be handed over between organizations.
But getting customers back is usually equally easy since there was never any fuzz when leaving so when they've become dissatisfied with the "cheap" options they don't remember leaving being a problem, regardless the winner is the cloud provider (but the costs are still small enough for each client that nobody is unhappy).