I've been feeling annoyed by async rust too, and have been brought back to Python for some of my side projects. That said, a lot of the cool features that I like from Rust feel tacked on in Python, so I've been looking at Ocaml. The ecosystem looks even worse than Rust, but it seems like it could be a solid replacement in terms of pure language features.
Have you looked at F#? If you like the MLish aspects of Rust but want to not have to deal with some of the manual memory management complexity it's pretty nice. There's access to the whole .NET ecosystem too, as well as really good tooling and IDE support, though not all .NET libraries written in / for C# feel totally natural to consume from F#.
Some of them going forward aren't even possible to consume from F# unless there is a C# shim, e.g. anything that relies on code annoations for code generators, or post .NET 8, interceptors.
