Because that would be stupid... the point is to automatically convert a bunch of C to rust Automatically then a programmer will convert the rest manually. All of the code ends up being rust.... with less man hours required to do the conversion.
The part of the driver in ring 0... must be there its literally just the miniport driver that directly talks with the hardware and that is all its allowed to do (implement the miniport API).
Linux distrobutions are by definition separate projects from most free software.... there are some excepts for things developed specificially by a certain distro but all in all no single distro develops all of its software in house... that is a fact.