> Google itself doesn't actually have any real API libraries for their cloud services. They autogenerate all API libraries for golang, which means they're not idiomatic, are convoluted to use, and the documentation is a jungle.

Are you sure? Google offers 2 Google Cloud APIs for Go:

- Google API Client Library for Go, which is auto-generated like you wrote;

- Google Cloud Platform Client Library for Go, which is intended to be idiomatically-designed.

See https://cloud.google.com/go/apis.