The fact that writing unsafe rust code is harder than unsafe C due to more rules? The fact that Rust has little support of nostdlib which is what the kernel is

The fact that writing unsafe rust code is harder than unsafe C due to more rules? The fact that Rust has little support of nostdlib which is what the kernel is using? There's also the fact that most of the time in drivers (in my limited experience) you almost always want unsafe things but I assumed noone would think or admit that one