So depending on your context, it may seem like the whole ecosystem depends on tokio, but if you look at say, embedded Rust, it makes a little more sense.

The system requirements for an async runtime on a workstation processor compared to say, an RP2040 look very different. But given the ability to swap out the backend, when I write async IO code for a small ARM M0 microcontroller, that code looks almost identical to what I'd be writing outside that context, but with an embedded focused runtime, ie embassy.

I can focus less on the runtime specifics as they use the same traits and interfaces. Compare this with say, using a small RTOS or rolling your own async environment, it's quite nice.

Much of what I need to learn to write the async code in embassy can cross over to other domains.