Define "needed" ? Code with async/await is radically simpler compared to without - this is not just basic sugar but really, really important due to rust's borrow semantics There is code I have written that required Rc/RefCell ceremony to get around the borrowchecker that will be completely handled by async/await.
You can read more about this here:
https://aturon.github.io/tech/2018/04/24/async-borrowing/
> performs worse than a basic epoll loop
There are open issues and afaik all of these are solvable problems with known/ theorized solutions.
> is more confusing, and less able to handle complex flow
Sorry, that's absolutely just not the case Even if "confusing" is subjective, you can not tell me that writing complex loops/ control flow is easier in futures than in async/await. Just look at the examples here:
https://docs.rs/dtolnay/0.0.4/dtolnay/macro._01__await_a_min...
People who are puzzled by async/await often fall into this camp.
It took c++ years to blow its complexity budge. Rust, "Hold my beer."