Insulating layer?

Rust provides a bunch of guarantees that C does not have a concept of, which thus are not checkable at compile time. The practical effect is that a significantly large class of problems just disappears (OK not by itself, you need to heed the compiler warnings and fix them), to the tune that Asahi Lina wrote a complete and mostly-bug-free driver for Apple's M1 basically from scratch in a few weeks (while she actually needed months in real time, she also hat to write all the infrastructure).

This kind of feat is basically impossible in C.

The people who insist of that part being written in Rust are *right*. It's less work to backport the whole Rust infrastructure to an older kernel, if you really think you have to do that (in a sane world you most emphatically would not), than to write that code in C. Not if you consider the subsequent hunting of bugs.