This still doesn't explain why the language of the compiler matters. I could write a C compiler in Pony-lang targeting a 30-year-old MCU were I so inclined. Th

This still doesn't explain why the language of the compiler matters. I could write a C compiler in Pony-lang targeting a 30-year-old MCU were I so inclined. The available compilers targeting your microcontroller certainly matter, though. You certainly still find lots of options that aren't Rust-compatible, but a non-trivial number microcontrollers are ARM or RISC-V based now, and can be targeted by LLVM/Rust.