Because most enterprise users would much rather have overages in billing than outages. The opportunity costs on any serious service I deploy dwarfs usage pricing, at least at the level a generic cloud can determine.

So it’s a feature the best customers don’t want, that adds risk to those customers deployments, to appease the worst customers.

At least historically. Perhaps Simon is right that the calculation has changed.

It’s not a binary decision though. Any sensible enterprise has many AWS accounts. Often hundreds or thousands. It’s the only clear separation of privilege.

There’s no reason for the majority of them to have an infinite budget cap. Prod? Sure. UAT? Why not. The sandbox environment Johnny just spun up to test some new agentic workflow? Hell no.

That's a reason to not force a hard budget cap on all of your customers, but it's not a reason to not offer one.