It's not unnecessary, though. In Go, a string cannot be nil, as you know; it is initialized to the value of an empty string. That's not true in any other languages, and even the Go AWS library cannot use that as a signal of intent, because you may have intended to use an empty string.

Granted, I don't know if there are any calls where an empty string is an actual valid parameter. But it seems Amazon is erring on the side of explicitness here.

I agree that the AWS library isn't ergonomic. But Go is forcing their hand, in my opinion.