When I've used GCP in the past this has really really annoyed me.

Someone told me some years ago that it was "impossible" for Google to apply an upper usage caps due to technical design reasons which I found absurd. You can build a globally distributed continent-scale SQL database with consistency guarantees, but you can't stop me paying more than X USD when my usage ticks over that? Huh?

It smelt much more to me like Google's business model made it impossible to stop customers spending money, not their engineering.

I voted with my wallet.