I feel like everyone involved in the Linux Kernel Rust world is ironically woefully unaware of how Rust actually works, and what it's actually capable of. I suspect that Rust gurus agree with me, but don't want to say anything because it would hurt Rust adoption in places where it actually is helpful (encryption algorithms...)

Kernels - and especially the Linux kernel - are high-performance systems that require lots of shared mutable state. Every driver is a glorified while loop waiting for an IRQ so it can copy a chunk of data from one shared mutable buffer to another shared mutable buffer. So there will need to be some level of unsafe in the code.

There's a fallacy that if 95% of the code is safe, and 5% is unsafe, then that code is only 5% as likely to contain memory errors as a comparable C program. But, to reiterate what another commenter said, and something I've predicted for a long time, the tendency for the "unsafe block" to become instrumented by the "safe block" will always exist. People will loosen the API contract between the "safe" and "unsafe" sides until an error in the "safe" side kicks off an error in the "unsafe" side.