Writing in another language doesn't come close to solving the problem - a modern OS sits between lots of differently-privileged processes and thousands of devices, most of which have DMA access to host memory (and which are thus "memory-unsafe" in any language). On the other hand, C does give you good low-level access, an enormous ecosystem, and a large number of potential contributors.

HN is fond of blaming C, but seldom has any awareness of why almost everything does use C. This is not to say that C is perfect, but replacing it needs deep expertise in the fields in which C is still dominant.

Which tells me that 1) the deficiencies are minor or 2) the benefits outweigh the deficiencies, or a combination.

Consider that virtually all well-known operating systems, device drivers, embedded systems all over the world use C for some reason, what are you saying would be a better choice?

I looked into rust when it first came out. I dissed it but then found it to be quite interesting. However, compared to C, it is used relatively nowhere by anyone. I don't believe rust has proved to be a non-hesitant replacement for C.