My understanding is that this decorator generates some class in the background that wraps the function into some remotely executable container thing, and handles the networking?
Since python is a dynamic language, and go is not, this would be impossible without codegen, generics or not, but go does have codegen facilities.
And the more immediate implication, that many OOP languages do (and seems to be going on in here) is that they handle asynchrony via some generic Awaitable[T] pattern.
Go does not do this, generally the way you handle asynchrony and abstract typed results is by using channels. You don't await on 'smart' objects, you read from channels (which are 'generic' in a way, but they are the few exceptions where go used to allow this behavior).