The author appears to contradict the very issue they argue, by presenting languages such as Go, Erlang or their own toy language. These languages hide the async / await constructs that are present in languages like Rust, Swift or Typescript. The former languages and runtimes have no function colouring problems, when working within their own SDKs. There are trade offs, and these “async” languages tend to be a bit more awkward when interacting with OS frameworks.