I will argue that Go's concurrency model is fundamentally flawed[0] precisely because its underlying mechanism is hidden from the user. If it wasn't for this model I would be using Go instead of C and probably instead of a lot of other alternatives.

Yes Go the language is boring and I like this idea, but the runtime is a black box, that I don't like so much.

[0]. For example: https://github.com/golang/go/issues/14592.