Continuations (which can be just closures following CPS conversion) can be used to construct co-routines, and so if you start with co-routines instead...
But callbacks and callback-based async/await force you to compress application state better, so you will get better performance out of that. No need for `call/cc` style continuations, just light-weight continuations, but this is mainly a mirage because in the callback model you do in fact have continuations, it's just that the continuation is only ever "the next step in processing this thing" rather than "the whole stack".
That is, with hand-coded CPS you get a very shallow stack to capture in continuations, so the continuations are very cheap.
But callbacks and callback-based async/await force you to compress application state better, so you will get better performance out of that. No need for `call/cc` style continuations, just light-weight continuations, but this is mainly a mirage because in the callback model you do in fact have continuations, it's just that the continuation is only ever "the next step in processing this thing" rather than "the whole stack".
That is, with hand-coded CPS you get a very shallow stack to capture in continuations, so the continuations are very cheap.