with green threads, every result is "delayed" and available exactly when you want it (i.e. as indicated by naive reading of the control flow in code) > eager e

with green threads, every result is "delayed" and available exactly when you want it (i.e. as indicated by naive reading of the control flow in code) > eager execution, interleave multiple concurrent tasks green threads give you that for free > deal with blocking blocking is an implementation detail; both async/await and green threads can be implemented on top of either traditional blocking IO, or callback/non-blocking IO I'd be even happier to discuss concrete code blocks / examples, that's where the superiority of green threads truly shines