Should be noted that Rust didn't have a 30 year head start unlike C, so it's obvious that it won't have support for every single embedded platform under the sun

Should be noted that Rust didn't have a 30 year head start unlike C, so it's obvious that it won't have support for every single embedded platform under the sun, at least not yet. It could in principle. And because C is more popular in embedded, new vendors are more likely to pick it for new platforms instead of Rust, which doesn't help.