I don’t think Coroutines would fit in with Go. There is a huge emphasis on simplicity. Coroutines add a massive amount of complexity. In addition, goroutines provide the best parts of Coroutines - cheap, easy to use, non-blocking operations - without a lot of the pain pints such as “coloring” or functions and issues with using things like mutexes.

Just the question of whether one should use a goroutine or a coroutine adds complexity.