> The Gemini API supports monthly spend caps at both the billing account tier and project levels. These controls are designed to protect your account from unexpected overages, and the ecosystem to ensure service availability
https://ai.google.dev/gemini-api/docs/billing#project-spend-...
Why is the default uncapped then other than the hopes of billing people who screw up or get exploited.
The problem is it's specific to that API and defaults to uncapped so people who aren't using it and haven't heard about the issues with the Firebase API keys probably won't have set them.