> Over here minors can't enter into debt contracts like credit cards

In basically all of the western world minors can enter into debt contracts, but are generally not seen as particularly creditworthy.

No, that's not legally permitted in many places. I was under impression that minors can't enter into debt contracts anywhere in EU, but that, too, was an incorrect assumption.

https://fra.europa.eu/en/publication/2017/mapping-minimum-ag...

I grew up in one of these "not under 18 even with parental consent" countries, so that coloured my view of the matter.

Minors can't get a credit card in the UK. In fact, it's one of the government approved age verification methods for that exact reason.

Think business accounts. The name on the card might be some agent of the company but they're not directly responsible for paying the debt. The business is responsible for the debt.

AWS doesn't check if your credit card will be able to handle a $5k charge before letting you rack that up, and in fact AWS doesn't support setting any spending limit.

You just have to put in any valid credit card at all when you sign up, use AWS, and at the end of the month you'll have a bill. At no point does your credit card limit or a spending limit enter into things.