Rust can cross-compile. I.e. you can build on an x86-machine and target aarch64.
> Is it projected what the eventual performance loss will be long term?
I don't know, but my understanding is that wasm ir is optimized for fast JIT compilation and not ideal for AOT workloads.
And compiling on demand on a target machine isn't great either because that means you're burning CPU cycles on compilation. Of course that can be worked around by turning wasm into machine code and distributing that to target machines. But then it's better to compile straight to machine code.