I came here to basically say something like this: if there's a hard limit, your business will basically shut down entirely. It's hard (impossible) for cloud providers to automagically shut down services based on each customer's priorities.

I don't think there's a magical solution to this. There might be a company that sets a $1K USD/month limit, forgets about it, and suddenly the cloud provider shuts down everything a year later, while "everyone" is unavailable or something like that.

There are so many scenarios, and I honestly feel that the cloud providers have decided on the most fool-proof solution both for them and their clients.