[kaba0]

Async-await is about concurrency, not parallelism. It can work in both a single-threaded and multi-threaded context, the latter exposing all the typical failure modes of multi-threaded code.

Also, Rust’s ownership model only prevents data races, that’s only the tip of the iceberg of race conditions, and I don’t think that any general model makes it possible to statically determine that any given multithreaded code is safe. Nonetheless, that’s the only way to speed up most kind of code, so possibly the benefits outweigh the cost in many cases.