I don't think cloud providers would just change their SDK or APIs without notice. It will break anyone using their SDK, not only go-cloud.
For your second point, it's normal for small startups to shop around and pick the cloud provider that's more suitable for their needs. For example on my last job at a small startup, we switched from AWS to GCP for cost reasons, and I implemented an abstraction (similar to go-cloud's) between S3 and GCS because of that.
For your second point, it's normal for small startups to shop around and pick the cloud provider that's more suitable for their needs. For example on my last job at a small startup, we switched from AWS to GCP for cost reasons, and I implemented an abstraction (similar to go-cloud's) between S3 and GCS because of that.