Wait I thought AWS made you pay if you got hit with a DDoS or even a moderate amount of traffic. It's just there is no cap on costs if you have any kind of autoscaling enabled. There use to be many posts complaining about surprise charges on AWS.
They were generous enough, but at the expense of uncertainty + you needing to play an active role in getting them to pay your bill. Depending on what sort of service you run, it may be a constant ordeal.
After getting some large CloudFront bills taken care of, I left and wondered what sort of person had the stomach it.