> Coroutines are a lifetime and performance nightmare that was originally designed in particular to accommodate embedded platforms with no runtime, but are all but useless for that use case due to how they allocate memory, and concepts are really just a substitution of one hacky way of doing overload resolution with another hacky way of doing it.

Coroutines were originally pushed by Microsoft, based on .NET's async/await model, and C++/CX concurrency on WinRT (COM evolution) runtime.

Hence why you will find several talks and papers from Gor Nishanov, during C++'s coroutines early days, or that .NET has a similar way of adding magic methods to a class to transform it into a coroutine aware type.