I've not had the experience that Rust libraries rely on platform specific behavior (ignoring things that specifically expose the capabilities of a platform spec

I've not had the experience that Rust libraries rely on platform specific behavior (ignoring things that specifically expose the capabilities of a platform specific like a HAL crate or an io_uring crate). I've had far less trouble than I anticipated getting up and running in embedded and WASM contexts. Have you had a different experience that's leading you to these views?