What would be helpful, would be if when you set up your account there was a default limit – as in an actual limit, where all projects stop working once you go over it - of some sane amount like $5 or $50 or even $500.
I have a handful of toy projects on AWS and Google cloud. On both I have budgets set up at $1 and $10, with notifications at 10% 50% and 90%. It’s great, but it’s not a limit. I can still get screwed if somehow, my projects become targets, and I don’t see the emails immediately or aren’t able to act on them immediately.
It blows my mind there’s no way I can just say, “there’s no conceivable outcome where I would want to spend more than $10 or more than $100 or whatever so please just cut me off as soon as I get anywhere close to that.”
The only conclusion I can come to is that these services are simply not made for small experimental projects, yet I also don’t know any other way to learn the services except by setting up toy projects, and thus exposing yourself to ruinous liability.