File operation in kernel (hello windows 2000- graphics). What can go wrong. Nevermind, it is android, it has other security problems.
Literally every file operation HAS to go through the kernel. This is implementing "what does it mean to read/write this special device file"
On the other hand, to be fair, a device driver itself (even though it is represented as a "special file") does not need to have the notion of a file system built into it.