Implicit coroutines are also problematic: https://glyph.twistedmatrix.com/2014/02/unyielding.html.

As applied to Go: https://blog.mozilla.org/services/2014/03/12/sane-concurrenc...

There are already "Result" colored and "Future" colored functions right now. Async/await just adds syntactical sugar.

Sometimes, problems are inherent. Especially in a systems language.