I used to think that I would never write C code again, but when I decided recently to build something that would run on ESP32 chips, I realized there wasn't any good reason for me to use Rust yet. ESP-IDF is built on C and I can write C code just fine. C compiles quickly, it's a very simple language on the surface, and as long as you minimize the use of dynamic memory allocation and other pitfalls, it's reliable.