Microsoft has an Azure SDK under their organization (https://github.com/Azure/azure-sdk-for-rust), but oddly, it's marked as "unofficial". It looks like Google doesn't have one for GCP, but there is a community-built one: https://github.com/Byron/google-apis-rs
Given all these companies are part of the Rust Foundation (https://foundation.rust-lang.org/members/), maybe I just expect more.