Google's API's have a way steeper learning curve than is necessary. So many of their APIs depend on complex client libraries or technologies like GRPC that aren't used much outside of Google.
Their permission model is diabolically complex to figure out too - same vibes as AWS, Google even used the same IAM acronym.
I don't see that dependency. With ANY of the APIs. They're all documented. I invoke them directly from within emacs . OR you can curl them. I almost never use the wrapper libraries.
I agree with your point that the client libraries are large and complicated, for my tastes. But there's no inherent dependency of the API on the library. The dependency arrow points the other direction. The libraries are optional; and in my experience, you can find 3p libraries that are thinner and more targeted if you like.