[the__alchemist]

On embededded, you can write straightforward asynchronous code without using *Async*. You do it using DMA, and interrupts, perhaps with static analysis etc. There are efforts to use Async on embedded rust to abstract these, but it's not required.

Of note re networking: My observation is that the Rust Async ecosystem only covers TCP and higher. There are loads of Async TCP, HTTP etc libs, but nothing that can do anything lower than that! At that point, you're looking at perhaps `socket2`, and `smoltcp`; the latter, of note, also works on embedded, and goes lower than TCP, despite its name.

My best guess is that a lot of people are using Rust for TCP and HTTP level web programming, eg servers, where spawning 100s or more IO-bound processes at once makes sense; the area where Async shines. Why I'm confounded: #1: Rust excels at low-level programming; ie it's one of a select group capable of this (Along with C, C++, ADA, and zig) #2: Web application programming in Rust has a long way to go to get to the level of Django and Rails. It only has Flask analogues.

Neither of those goals are served by the existing Async-based ecosystem; it occupies a spot in between.