I can't see any features listed that enable me to control costs to prevent surprise bills. If a site got submitted to HN and hugged to not-to-death-because-it-autoscales then I'd wake up to a bunch of alerts and massive outbound bandwidth bill. I don't want that. I want something that stops that happening.
If the App Platform doesn't have that feature, and it isn't planned, that's OK but I'd argue that isn't really preventing a surprise bill as the marketing site claims. A warning isn't quite the same as prevention.
This is exactly the sort of thing I'm talking about, but for money rather than computing resources or bandwidth. I'd like a feature that where the requirement is effectively "Fall back to a serving sorry-I'm-poor.html instead of the app if the total monthly bill has exceeded $xxx". For a side project I'm more interested in not paying an unexpected bill than getting traffic.
I think for most companies, it's better to set the expectation that the service costs money, bursts will cost more money, and then forgive outlier charges once or twice. It's tremendously difficult to compete against the AWS's of the world, putting work into features specifically to minimize how much people spend seems like a good way to fail a company.
In those cases, the users will either not know or not think about such expense limits.
The solution is to set relatively strict limits by default and even occasionally warn users about unused/underutilized resources.
But as you said: such features are bad for the bottom line .
And I can appreciate the enormous difficulty of competing with the big 3.
For people who are inexperienced or don't give it much thought, just waiving their overage fees creates a really nice experience. We've had multiple instances of people asking why their bill is so high and being relieved/excited when we explained it and made it go away. People love when we're responsive to problems.