There is also still a lot of low-level proprietary code developed in C. I would guess far more than what is developed in Rust.

I fully agree about your last point. The proposed solutions to some of the deficiencies of C are sometimes worse than the disease while its benefits are often exaggerated, at the same time adding unnecessary layers of complexity that will haunt us for decades. In contrast, my hope would be to to carefully revise the things we have, but this takes time and patience.