Well, the routes might manifest somewhere as files, but I don’t expect anyone to be able to viably parse them without commands like ip or ifconfig (or know where the files even are).
Some devices (like disks for example) are very straightforward to use as files, while some other special files (like USB devices) are so weird/ugly to use that everyone uses tools/libraries to access them (like libusb).
This is very off-topic, but there’s a great talk by Benno Rice that talks about this (among many others): youtu.be/9-IWMbJXoLM