Hubris, an embedded RTOS-like used in production by Oxide, has ~4% unsafe code in the kernel last I checked. There’s a ring buffer implementation that has one unsafe, for unchecked indexing: https://github.com/oxidecomputer/hubris/blob/master/lib/ring... (this of course does not mean that it is the one ring buffer to rule them all, but it’s to demonstrate that yes, it is at least possible to have one with minimum unsafe.)
It’s always a way lower number than folks assume. Even in spaces that have higher than average usage.
I've always had the impression that people who haven't actually tried to write low-level code in Rust to try to find out where the actual boundary of where they would need unsafe is tend not to realize how far you can push something and build safe abstractions on top of it. Almost every time I've had to wrap an unsafe API, I've been able to find a way to eliminate at least one of the invariants that are documented as needed for safety from propagating upwards, and there have been plenty of times that the specific circumstances of my use-case allowed me to eliminate it entirely.
The entirety of safe Rust is built upon unsafe Rust that's abstracted like this. The fact that you sometimes need unsafe isn't a mark against Rust, but literally the entire premise of the language and the exact problem it's designed to solve.