"good performance" is a relative term. You may consider Haskell or Scala having "good performance" but for others having garbage collection itself is a big no. So you are either left with Rust's approach where you limit the programmer, or C++'s approach where you leave memory management mostly to the programmer
My response was focussed on the part of the challenges of async logic. And what OP essentially said is that Rust does not only help performance because of the ownership model (vs. garbage collection), but also because it makes it easy to come up with correct and performant solution to async-related problems.
My point was that, when ignoring the performance benefits of ownership model vs. garbage collection, a language like Haskell or Scala makes a performant and correct solution for async problems easier than Rust does - at least at the current point in time.
