> A silly mistake can cost you so much money and they tend to word the e-mails strongly.

They tend to word emails strongly to affect action.

As for the cost overruns: I don't know anyone who wrote one of those blog posts (or emailed support) who didn't get their bill refunded.

We can argue about spending caps or hard limits (which people generally dislike for their production apps), but the people side of the business is (or at least was) solid.

Source: worded emails strongly to affect action at Firebase and refunded a number of bills.