I will not be at all surprised if firmware stays in C until Rust has been practical for use in firmware for several years as well. I don't doubt it'll happen, I haven't written a line of assembly for my firmware in a decade either, but consider how many hundreds of thousands of lines of C there are in the libraries for just one target architecture.

It sounds cool and useful and I'm looking forward to it, but every time I start asking around if Rust is worth the effort the answer from people who use Rust a lot is "not really" because my projects aren't big complex firmware beasts. I am not surprised that a firmware developer with expertise in C can easily find work.