I didn't mean to imply that. A hard limit at X that stays inactive <X, and at >X, leaves you with a bill of X and an outage is the easiest approach from a technical side: Terminate the service when X is reached, and bill exactly what was provided. It is something you would instantly come up with when asked to implement a cost limit, and you don't for a second put yourself in the customer's position.

Of course cloud vendors do put themselves in the customer's position, and that's why they say that customers would not be happy with a limit, even though they are asking for it.