My day job is writing Rust code for microcontrollers.
What you're saying isn't wrong, it's just that... embedded development is incredibly diverse. LLVM doesn't support as many platforms as GCC does, and even once LLVM gets support for something, we need to do some work in Rust to get things working; support isn't automatic.
If you get to pick what your hardware is, Rust is fantastic. If you don't get to pick... it's a roll of the dice.
What you're saying isn't wrong, it's just that... embedded development is incredibly diverse. LLVM doesn't support as many platforms as GCC does, and even once LLVM gets support for something, we need to do some work in Rust to get things working; support isn't automatic.
If you get to pick what your hardware is, Rust is fantastic. If you don't get to pick... it's a roll of the dice.