And frankly any pay-as-you-go scheme should be regulated to have maximum spending limit setting. Not only in IT.
You're right in that there's a few services that expose this complexity directly, the ones where you're paying for actual storage, but this is just complex, not impossible.
For one thing, storage costs are almost always static for the period, they don't scale to infinite in the same way.
If you're worried about getting a big bill, and you don't care if it gets shut off when you're not using it, why don't you shut it down yourself?
AWS made the tradeoff to keep the lights on for customers and if there is a huge bill run up unintentionally and you contact them with it they refund it. I've never experienced them not doing this when I've run up five figure bills because of a misconfiguration I didn't understand. I don't think I've ever even heard of them not refunding someone who asked them for a refund in good faith.
